Distal Renal Denervation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Distal Renal Denervation (NCT02667912), a randomized na study. The primary outcome is Changes of 24h-mean Systolic BP Assessed by Ambulatory Blood Pressure Monitoring (ABPM).

2. Clinical Question

The registry describes the objective as comparing a distal approach, with treatment performed primarily in segmental branches, with a conventional approach in which treatment is distributed within the main renal artery trunk. The clinical question is therefore comparative: whether the two approaches differ on the specified blood-pressure measure over the stated follow-up period. The posted result does not compare either procedure with no procedure or with a medication-only group.

The primary outcome is defined as a change from baseline, rather than a single blood-pressure value at follow-up. The registry identifies the population for this outcome as participants who completed follow-up without serious protocol violations. That definition matters when interpreting the results: the primary comparison is for this per-protocol population, not necessarily every participant enrolled or randomized. Details of the protocol violations and their effect on inclusion are not reported in the registry record.

The central statistical question is about the estimated between-group difference and how precisely it is measured. The point estimates and intervals can describe the posted data, but they do not by themselves establish the reason for any difference or how the result would apply beyond the enrolled study population.

3. Trial Design

The registry lists this as a randomized, triple-masked, parallel-group study. It records 55 participants enrolled and a completed study status. The phase is listed as NA. The sponsor is Tomsk National Research Medical Center of the Russian Academy of Sciences. The record gives a study start of 2013-01 and a primary completion date of 2016-07.

Participants were allocated to one of two procedural groups. In the distal group, endovascular denervation was performed on segmental branches of the renal artery. In the conventional group, it was performed on the main trunk of the renal artery. The registry’s description identifies the anatomical location of treatment as the key planned distinction between the groups. It does not report further procedural details here, so the comparison should not be interpreted as a test of other procedural variations.

For the primary endpoint, the posted arm summaries include 27 participants in the distal group and 24 in the conventional group. These are the endpoint analysis counts, and the primary population is described as per protocol. The registry does not report how participants were distributed across all stages of the study, why any enrolled participants were absent from this analysis, or whether the same analysis population was used for every outcome.

Randomization is intended, in general, to make treatment groups comparable on average with respect to both measured and unmeasured factors. Masking can reduce the influence of expectations on study conduct or assessment, but the registry does not identify who was masked or how masking was maintained. The original randomization procedure, allocation concealment details, and planned sample-size justification are not reported in the registry record. Those omissions limit what can be concluded about implementation of the design from this record alone.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The subjects who completed 6 months follow up without serious violations of the study protocol - per protocol set

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Changes of 24h-mean Systolic BP Assessed by Ambulatory Blood Pressure Monitoring (ABPM), measured over From baseline to 6 months.

The primary endpoint is the change in 24h mean systolic blood pressure, assessed by ambulatory blood pressure monitoring, from baseline to 6 months. Systolic blood pressure is the pressure measured during the heart’s contraction; the endpoint summarizes its mean over the stated monitoring period. The registry reports the endpoint in mmHg and summarizes it as a mean with a standard deviation.

Using change from baseline focuses the comparison on how the measured outcome shifted over follow-up, rather than only comparing follow-up values. The between-group comparison asks whether the average change differed between distal and conventional renal denervation. The registry’s primary population is restricted to participants who completed 6 months without serious protocol violations, so the result describes that per-protocol analysis population.

In general, ambulatory monitoring records blood pressure over an extended period outside a single clinic measurement. This can provide a broader summary of blood pressure during the monitoring period. That is a general description of the measurement approach, not an additional result from this trial. The registry does not report further details about the monitoring schedule or processing rules.

The standard deviation describes how much individual participants’ changes varied around the group mean; it is not itself a measure of precision for the between-group estimate. Precision is better assessed using a confidence interval for the comparison. The endpoint and its analysis therefore need to be read together: the mean change describes the observed group-level pattern, while the interval indicates the range of differences compatible with the posted data and analysis.

7. Results Posted in the Registry

• Conventional Renal Denervation: mean 10.30 versus 21.10 on control; difference -10.80 (95% CI -20.98 to -0.62), standardized effect d = -0.58; z-test p = 0.038.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Changes of Arterial Resistance Index Measured by Doppler Flowmetry in the Right Segmental Renal Arteries

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Conventional Renal Denervation: mean 0.02 versus 0.02 on control; difference -0.00 (95% CI -0.04 to 0.04), standardized effect d = -0.02; z-test p = 0.957.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Conventional Renal Denervation and the control. The interval gives the range of effects that remain compatible with the data.

Changes of Arterial Resistance Index Measured by Doppler Flowmetry in the Left Segmental Renal Arteries

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Conventional Renal Denervation: mean 0.03 versus 0.01 on control; difference 0.03 (95% CI -0.01 to 0.07), standardized effect d = 0.39; z-test p = 0.196.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Conventional Renal Denervation and the control. The interval gives the range of effects that remain compatible with the data.

Changes of Serum Creatinine

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Conventional Renal Denervation: mean 2.30 versus 2.00 on control; difference 0.30 (95% CI -7.19 to 7.79), standardized effect d = 0.02; z-test p = 0.937.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Conventional Renal Denervation and the control. The interval gives the range of effects that remain compatible with the data.

The registry lists a broad set of secondary outcomes, including adverse events, renal arterial resistance indices, serum creatinine, and estimated glomerular filtration rate. It posts 23 secondary outcomes in total, but detailed numerical summaries are available for only a subset. The available continuous outcomes generally do not produce a consistent secondary pattern that independently reinforces the primary comparison. Their between-group estimates are uncertain, and the posted analyses do not establish clear differences across these measures.

The secondary measures address different aspects of the study from the primary blood-pressure endpoint. Arterial resistance indices and renal laboratory measures can add context, but they are not interchangeable with the primary outcome. The results should therefore be read as complementary observations, not as substitutes for the primary comparison. The registry does not report numerical results for every listed secondary outcome, including estimated glomerular filtration rate; those results are not reported in the registry record.

The secondary analyses carry less weight for confirmatory interpretation because many outcomes are considered. When several outcomes are tested, the chance of at least one apparently unusual result can increase unless a suitable multiplicity strategy is planned and applied. The registry record does not report a multiplicity adjustment or a hierarchy for interpreting the secondary outcomes. Their p-values should consequently be treated as exploratory or descriptive rather than as independent confirmation of the primary finding.

The posted secondary results also have varying analysis counts. These differences mean that precision and the available data can vary by outcome. Reasons for the varying counts and details of missing-data handling are not reported in the registry record. Taken together, the secondary outcomes broaden the descriptive picture but do not remove the uncertainty around the primary estimate or establish a uniform effect across outcome domains.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Number of Adverse Events
• Number of Adverse Events
• Changes of Arterial Resistance Index Measured by Doppler Flowmetry in the Right Segmental Renal Arteries
• Changes of Arterial Resistance Index Measured by Doppler Flowmetry in the Left Segmental Renal Arteries
• Changes of Serum Creatinine
• Changes of Serum Creatinine
• Changes of Estimated Glomerular Filtration Rate (eGFR)
• Changes of Estimated Glomerular Filtration Rate (eGFR)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is a continuous measure: change in 24h mean systolic blood pressure from baseline to 6 months. The registry summarizes each group with a mean and standard deviation. A mean gives the average observed change in that group. A standard deviation describes the spread of individual observations around that average. It is not the standard error of the mean, and it does not directly describe uncertainty in the difference between groups.

What does the mean difference represent?

A mean difference subtracts one group’s average from the other’s. The posted recalculation uses conventional minus distal, giving -10.8 mmHg. The sponsor’s reported result is ordered in the other direction and reports a positive 10.8 difference in final values. A sign change can result from reversing the subtraction order; it does not, by itself, indicate that the analyses disagree about which group had the larger value. Always check the stated contrast and outcome definition before interpreting the sign.

The primary endpoint is a change score, while the sponsor’s reported analysis is labeled as a comparison of final values. These are distinct ways of formulating a comparison. The posted recalculation is a simple, unadjusted calculation from summary statistics, so it does not reproduce any individual-level adjustment or other modeling that may have been used in the sponsor’s analysis. The registry lists the sponsor method as a two-sided t-test. More detailed model specifications are not reported in the registry record.

What does a two-sided test assess?

In general, a two-sided test evaluates departures in either direction from the null value, rather than testing only for a difference in one prespecified direction. The sponsor’s reported analysis is described as a two-sided t-test. The recalculated p-value is also presented as an unadjusted comparison. A p-value summarizes how incompatible the observed data are with the null hypothesis under the assumptions of the test. It is not the probability that the null hypothesis is true, and it does not describe the magnitude or clinical importance of a difference.

The sponsor reports p = 0.045 for its final-value comparison. The recalculation reports p = 0.038 for the change summaries. These figures relate to different analysis formulations, so small differences between them are not necessarily a contradiction. The registry does not report enough detail to determine every reason for the difference between the analyses. The discrepancy indicator is false, but the posted sponsor analysis and the recalculation still need to be described according to their respective outcome definitions.

How should the confidence interval be read?

A confidence interval expresses uncertainty around an estimated difference. In general, a 95% confidence interval is generated by a procedure that, under its assumptions and repeated use, would cover the target value at the stated rate. It is not a probability statement about this particular interval after it has been calculated. A narrower interval indicates greater precision than a wider interval, all else equal. The sponsor’s interval is 0.3 to 21.4 for its reported final-value contrast. The recalculated interval is displayed with the comparison in the results material.

Intervals should be interpreted on the same scale and in the same direction as their estimate. The sponsor’s positive estimate and the recalculated negative estimate use reversed contrast order. Both intervals are associated with their own analyses, and the outcome formulations differ. The point estimate alone can obscure this distinction; reading the interval, outcome definition, and contrast direction together is more informative.

Why does the analysis population matter?

The primary population is explicitly defined as participants who completed 6 months of follow-up without serious protocol violations. This is a per-protocol population. In general, excluding participants after randomization can affect the balance created by random assignment, depending on the reasons for exclusion and their relation to outcomes. The registry does not report the detailed reasons for exclusions or a primary intention-to-treat analysis in the information. It is therefore not possible to assess the impact of those choices from this record alone.

Different endpoints can have different numbers of observations. The secondary results show varying analysis counts across measures. That can occur for many reasons, but the specific reasons are not reported in the registry record. A reader should not assume that every endpoint was measured in every participant or that missing observations were handled in the same way across outcomes.

These statistical methods describe group averages and uncertainty; they do not establish a mechanism for the observed pattern. The randomized parallel-group design supports a comparative interpretation, but the size and precision of the estimate, the per-protocol population, and the analysis choices all remain relevant. The posted primary result is best read as an estimate for this endpoint, population, and follow-up period, rather than as a definitive statement about all related outcomes.

11. Confidence Intervals and Precision

The primary point estimate gives a concise summary of the difference between the group averages, but it does not show how much uncertainty surrounds that estimate. The recalculated interval is displayed in the comparison material. It lies below zero when the contrast is expressed as conventional minus distal. The sponsor’s reported 95% confidence interval for the final-value comparison runs from 0.3 to 21.4, with the contrast expressed in the reverse direction. Both intervals therefore need to be interpreted with their own contrast ordering in mind.

A confidence interval is useful because it presents a range of values compatible with the data and analysis, rather than implying that the observed estimate is exact. The sponsor interval includes values relatively close to zero as well as larger positive differences. That span conveys uncertainty about the magnitude, even though the interval is on one side of zero. The recalculated interval also shows the uncertainty around the mean-change comparison; consult the displayed result rather than treating the point estimate as the only relevant quantity.

The endpoint analysis is based on 27 participants in the distal group and 24 in the conventional group. The standard deviations, 19.3 and 17.8 mmHg, show that individual changes varied within both groups. A relatively limited analysis population combined with participant-level variation can leave a broad range of between-group effects compatible with the data. This is a general statistical consideration, not a claim about the original design rationale.

Precision is distinct from clinical importance. The interval does not determine whether any particular difference matters to patients, and that judgment is not reported in the registry record. Nor does an interval resolve limitations arising from the per-protocol population, outcome handling, or follow-up horizon. The point estimate and interval should be read together with those features of the study.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size table and curve are planning illustrations based on the observed effect, not a record of the trial’s original design calculation. The figures are participants per arm for 80% power and participants per arm for 90% power; they are not total event counts. The stated planning assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Each row uses a stated fraction of the observed effect as the effect to detect.

The 80% power column describes the number of participants per arm that the planning calculation estimates would be needed for an 80% chance of detecting the specified effect under those assumptions, if that effect were the true effect and the model assumptions held. The 90% column makes the analogous illustration for a higher probability of detection. These are prospective planning quantities, not descriptions of the probability that the completed trial’s result is true.

The rows show planning at 100%, 75%, and 50% of the observed effect. As the assumed effect becomes smaller, more participants are needed to distinguish it from random variation with the same planning criteria. The curve visualizes this relationship; it should be interpreted alongside the table and its assumptions, not as a new observed trial result.

The registry does not report the original sample-size justification or the design assumptions used for this study. The displayed calculations must not be read as evidence that the trial was planned to have a particular power, or as an estimate of observed power. This is not observed power.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -10.800; pooled standard deviation σ = 18.611.
2. n = 2 × (1.96 + 0.842)² × 18.611² / -10.800² = 46.6, rounded up to 47 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -10.8                      # observed difference in means
sigma <- 18.610979862129                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(2667912)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 47 (80% power), 63 (90% power)
 75% of observed effect: n per arm = 83 (80% power), 111 (90% power)
 50% of observed effect: n per arm = 187 (80% power), 250 (90% power)
power.t.test: 47.6 
Simulated power at n = 47 per arm: 0.791 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The sponsor’s primary analysis is reported as a two-sided t-test of mean difference in final values. It gives a difference of 10.8, a 95% confidence interval from 0.3 to 21.4, and p = 0.045. The posted recalculation instead compares the group summaries for change from baseline and expresses the contrast as conventional minus distal. It gives -10.8 and p = 0.038. Reversing the contrast order changes the sign, so the directions are consistent when each result is read using its stated ordering.

The numerical estimates have the same magnitude as reported, but the analyses are not identical: one is described as a final-value comparison and the other is an unadjusted recalculation from change summaries. The p-values and intervals should therefore be kept attached to their respective methods rather than combined or presented as duplicate estimates of precisely the same calculation. The posted recalculation is useful as a transparent check on the summary data, while the sponsor’s result is the analysis reported by the study record.

The record does not report further detail about adjustments, model specifications, or the full analysis procedure behind the sponsor’s result. That prevents a fuller reconciliation of the two approaches. The discrepancy indicator is false; there is no basis to claim that the sponsor’s analysis conflicts with the recalculation. Still, the analysis definitions and contrast directions should remain explicit when describing either result.

15. Multiplicity, Missing Data and Analysis Populations

The registry lists numerous secondary outcomes and reports analyses for some of them. Testing multiple outcomes creates a multiplicity concern: in general, when more hypotheses are examined, the chance of obtaining at least one small p-value by chance can rise. A prespecified hierarchy, adjustment, or other strategy can address this concern, but the registry record does not report a multiplicity plan or adjustment. The posted secondary p-values should therefore not be read as if each were the only analysis conducted.

The primary endpoint is identified, which makes it possible to distinguish the principal comparison from the additional outcomes. However, details of the statistical analysis plan, including whether there were prespecified interim analyses, are not reported in the registry record. The record also does not report whether outcome definitions or analyses changed over time. No assumptions about those matters can be made from the posted results alone.

The primary analysis population is described as per protocol, consisting of participants who completed 6 months without serious protocol violations. The registry does not report a corresponding intention-to-treat estimate in the information. It also does not provide a detailed accounting of exclusions, protocol violations, or the timing and reasons for missing observations. These details matter because exclusion or missingness after randomization can affect the comparability of groups and the interpretation of the estimate.

Secondary analysis counts differ across measures, but reasons for those differences and the methods used to handle missing data are not reported in the registry record. It is not possible to determine whether missing values were imputed, whether analyses used only observed cases, or whether other procedures were applied. The fact that different counts appear does not by itself identify the cause.

These reporting gaps do not negate the posted estimates, but they limit assessment of how robust the analyses are to choices about multiplicity, missingness, and population. The most defensible reading is to focus on the stated primary outcome and population, describe its uncertainty, and treat the additional analyses with appropriate caution.

16. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: post-punctional pseudoaneuryzm (3.7%).

The registry reports one serious adverse event among 27 participants at risk in the distal renal denervation group and none among 24 participants at risk in the conventional group. It reports no other adverse events in either group. These figures describe the posted event counts and at-risk groups; they do not establish that an event was caused by a procedure or that the procedures have equivalent safety profiles.

The record identifies “Post-punctional pseudoaneuryzm” as a serious-event term and reports 3.7%. The registry does not provide further detail about event timing, severity beyond its serious classification, management, or attribution. Death counts are not reported in the registry record. The listed number-of-adverse-events outcomes appear more than once in the registry summary, but the event data should be interpreted from the posted safety figures rather than inferred from the outcome titles alone.

Safety comparisons from small groups can be imprecise, especially when events are uncommon. A zero count in one group does not prove that the underlying risk is zero, and the observed counts are not enough to establish a reliable difference between groups. These data summarize the recorded events during the study; the registry record does not provide a longer-term safety assessment.

17. What the Result Does, and Does Not, Mean

The primary result describes a difference in average change in 24h mean systolic blood pressure between the two randomized procedural groups over the period from baseline to 6 months. In the posted change summaries, the distal group’s mean change is larger than the conventional group’s, and the recalculated comparison is statistically distinguishable from zero under its unadjusted analysis. The sponsor’s reported final-value analysis also gives an interval on one side of zero when expressed in its contrast direction.

This result does not mean that every participant experienced a change like the group average. The standard deviations show that individual changes varied, and the confidence intervals leave uncertainty about the size of the between-group difference. Nor does the result identify why the group averages differ. The registry record does not provide evidence that isolates a mechanism or separates the anatomical treatment location from all other possible influences.

The result is specific to the primary endpoint, the 6-month timeframe, and the per-protocol population. It cannot be extended from these data alone to longer-term outcomes, other blood-pressure measures, all participants enrolled, or other populations. The trial compares distal with conventional renal denervation; it does not include a no-procedure comparator in the listed arms. Thus, the posted comparison addresses relative results between these two approaches, not their effects against no intervention.

Secondary outcomes and adverse-event summaries provide additional context, but they do not transform the primary result into a comprehensive assessment of every possible benefit or harm. Some secondary results are not reported numerically in the registry record, and details about multiplicity and missing-data handling are unavailable. The appropriate interpretation is therefore bounded: the record supports a reported difference on the stated primary measure, while leaving uncertainty about magnitude and broader implications.

This is a statistical description of the posted trial data, not a treatment recommendation. Whether the observed difference is important in a clinical setting is not established by the p-value or confidence interval alone, and that judgment is not reported in the registry record.

18. Why This Trial Matters Statistically

This trial is statistically interesting because it compares two procedural strategies that differ in the anatomical location of renal denervation. The randomized parallel-group design frames a direct between-group question, rather than asking whether one group changed over time in isolation. That distinction is important: a within-group change alone would not show whether the change differed from what occurred in the comparison group.

The primary endpoint is a continuous change measure, and the posted summaries allow readers to inspect the group means, variation, and a direct contrast. The recalculated comparison is transparent and can be checked against the posted summary statistics. The sponsor’s analysis adds the result reported in the registry, while its final-value formulation reminds readers that different analysis choices can yield estimates that should not be treated as identical.

The study also illustrates why statistical significance is not the same as precision. The primary comparison has a p-value below 0.05 in both reported formulations, but the confidence intervals still encompass a range of possible effect sizes. Sample-size planning illustrations based on the observed effect show why smaller target effects require larger studies under the stated assumptions; they do not tell us what the original design expected or how much power this completed study had.

Finally, the registry highlights the importance of knowing the analysis population and the reporting plan. The primary result is per protocol, secondary outcomes are numerous, and details of missing-data and multiplicity handling are not reported. Those details affect how confidently secondary patterns can be interpreted and how broadly the primary result should be generalized. The trial is therefore a useful case for reading estimates, intervals, populations, and reporting gaps together rather than reducing the conclusion to a single p-value.

19. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The primary analysis is restricted to a per-protocol population: participants who completed 6 months without serious protocol violations. The registry does not report the detailed reasons for exclusions or a corresponding intention-to-treat result. It is consequently difficult to assess whether exclusion after randomization affected the balance between groups or the interpretation of the estimate.

The primary endpoint analysis includes 27 participants in the distal group and 24 in the conventional group, while secondary outcomes have different counts. The registry does not explain the varying counts or report detailed missing-data methods. The uncertainty intervals provide information about sampling variation under the analyses, but they do not resolve possible bias from missing observations or exclusions.

The sponsor’s analysis is a final-value comparison, whereas the posted recalculation uses the change summaries. Their contrast directions are reversed, and the analysis formulations differ. The available record does not report sufficient statistical detail to fully reconcile every methodological choice. This limits how directly the estimates can be compared beyond their broadly aligned direction.

Many secondary outcomes are listed, but a multiplicity strategy is not reported. Secondary findings therefore have less confirmatory weight, particularly when several comparisons are examined. Numerical details for every listed outcome are not available in the registry record, including results for estimated glomerular filtration rate.

The endpoint is reported at 6 months, and longer-term results are not included in the information. Details of masking implementation, allocation concealment, original sample-size justification, and interim analyses are also not reported in the registry record. These limitations concern what can be evaluated from the record; they do not establish that a particular procedure or analysis was or was not carried out.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Distal Renal Denervation — NCT02667912.
• Registry record last updated 2021-10-25; status last verified 2021-10.
• Results first posted 2019-02-01.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

23. Record Summary

NCT02667912 is a completed randomized, triple-masked, parallel-group study of distal versus conventional renal denervation for resistant hypertension. The registry records 55 participants enrolled. The primary endpoint is change in 24h mean systolic blood pressure from baseline to 6 months, assessed by ambulatory monitoring in a per-protocol population.

The posted primary summaries show a larger mean change in the distal group, with an unadjusted recalculation and a sponsor-reported final-value analysis both presenting a between-group difference in their respective contrast directions. The intervals communicate uncertainty about its magnitude. Secondary outcomes and safety figures add context, but multiplicity, missing-data methods, and several design details are not reported in the registry record.