Safety and Efficacy Study of the Svelte Drug-Eluting Coronary Stent Delivery System: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Efficacy Study of the Svelte Drug-Eluting Coronary Stent Delivery System (NCT01788150), a randomized na study. The primary outcome is Angiographic In-Stent Late Lumen Loss (LL).

2. Clinical Question

The study was described as a prospective, randomized, active-control, multicenter trial of safety and efficacy. Its stated objective concerned patients with single, never previously treated coronary artery lesions. The primary measure is an angiographic measure of change in the lumen within the stented segment. It is not itself a direct measure of symptoms, functional status, or longer-term clinical events.

The registry lists coronary artery disease as the condition and coronary stenting as the intervention. It does not report detailed eligibility criteria, the number of participating centers, or a more specific definition of the primary-outcome analysis population. Those details are not reported in the registry record.

3. Trial Design

This was a randomized, parallel-group, active-control trial with no masking. The registry lists an enrollment of 159 and identifies the study as completed. The study began in 2013-01, and primary completion is listed as 2014-05. The phase is recorded as NA. The sponsor is Svelte Medical Systems, Inc.

Participants were assigned to coronary stenting with either the Svelte Drug-Eluting Coronary Stent or the Medtronic Resolute Integrity Drug-Eluting Stent. The brief summary describes the trial as prospective and multicenter. The registry does not report how randomization was generated or concealed, the number of centers, whether treatment assignment could be concealed from outcome assessors, or the planned follow-up schedule beyond the stated outcome timeframes.

The primary outcome was angiographic in-stent late lumen loss, measured in millimeters at 6 months post-procedure. The posted primary outcome data include 89 participants in the Svelte arm and 40 in the Medtronic arm. These outcome denominators differ from the enrollment total; the registry record does not explain the difference. The safety record uses separate at-risk denominators of 108 and 51, which also differ from the primary-outcome denominators. No reason for these distinct denominators is reported in the registry record.

Several secondary outcomes are listed, including target lesion revascularization, composites involving death and myocardial infarction, stent thrombosis, acute success, restenosis, and angiographic measurements. The listed secondary event outcomes include a timeframe of 1 year post-procedure. The registry includes outcome listings but does not report a detailed statistical analysis plan, a prespecified hierarchy for outcomes, or the original design assumptions used to set enrollment. No further detail about treatment adherence, crossover, or follow-up completeness is reported in the registry record.

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

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 Angiographic In-Stent Late Lumen Loss (LL), measured over 6-months post-procedure.

The primary endpoint is angiographic in-stent late lumen loss (LL) at 6 months post-procedure, reported as a mean in millimeters with a standard deviation. The registry defines the measurement as taken either within the stented segment or within 5 mm proximal and distal to the stent edges. It is therefore a measure of lumen change in the treated coronary segment rather than a count of clinical events.

In general, angiographic late lumen loss is used to describe the degree of lumen narrowing that occurs after a stent procedure over the specified follow-up period. A mean summarizes the average measurement across the participants included in the outcome analysis. The standard deviation describes how dispersed individual measurements are around that mean; it does not describe the uncertainty in the difference between arms.

For the Svelte arm, the registry reports a mean of 0.09 mm and a standard deviation of 0.31 mm among 89 participants. For the Medtronic arm, it reports a mean of 0.13 mm and a standard deviation of 0.27 mm among 40 participants. The endpoint provides an objective angiographic comparison at a defined follow-up time. It does not, by itself, establish whether participants experienced symptoms, needed another procedure, or had other clinical outcomes. The registry does not report the clinical interpretation or a threshold for a meaningful difference in this measure.

7. Results Posted in the Registry

• Medtronic Resolute Integrity Drug-Eluting Stent: mean 0.13 versus 0.09 on control; difference 0.04 (95% CI -0.07 to 0.15), standardized effect d = 0.13; z-test p = 0.458.

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.

Number of Participants Clinically-driven Target Lesion Revascularization (TLR)

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Medtronic Resolute Integrity Drug-Eluting Stent: 2.0% (1/51) versus 1.9% (2/108) on control; risk difference 0.1 percentage points (95% CI -4.5 to 4.7), risk ratio 1.06 (0.10–11.41); unadjusted two-proportion z-test p = 0.962.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Medtronic Resolute Integrity Drug-Eluting Stent and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants Composite of Cardiac Death, MI Attributed to the Target Vessel and Clinically Driven Target Lesion Revascularization

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Medtronic Resolute Integrity Drug-Eluting Stent: 7.8% (4/51) versus 3.7% (4/108) on control; risk difference 4.1 percentage points (95% CI -4.1 to 12.3), risk ratio 2.12 (0.55–8.13); unadjusted two-proportion z-test p = 0.265.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Medtronic Resolute Integrity Drug-Eluting Stent and the control. The interval gives the range of effects that remain compatible with the data.

Number of Participants Composite of All-cause Mortality, Any MI and Any Revascularization, Target Vessel Revascularization or Revascularization of Non Target Vessels

• Endpoint type: Binary: the number of participants with the event, compared as proportions.
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Medtronic Resolute Integrity Drug-Eluting Stent: 17.6% (9/51) versus 16.7% (18/108) on control; risk difference 1.0 percentage points (95% CI -11.6 to 13.6), risk ratio 1.06 (0.51–2.19); unadjusted two-proportion z-test p = 0.878.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Medtronic Resolute Integrity Drug-Eluting Stent and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes broaden the assessment beyond the primary angiographic measurement. They include participant counts for clinically driven target lesion revascularization and composites involving cardiac death, myocardial infarction, and revascularization, alongside other listed measures such as stent thrombosis and angiographic outcomes. Several listed outcomes concern events through 1 year post-procedure. These measures address clinical events and additional aspects of the treated segment, rather than replacing the primary endpoint.

For the secondary comparisons with numerical estimates, the reported confidence intervals span no difference. The directions and sizes of the point estimates do not form a strong, precise pattern that resolves the primary result. This is consistent with the primary comparison's uncertainty: neither the primary endpoint nor the available secondary comparisons establish a clear difference between the stent groups. The endpoints are distinct, however, so secondary event results cannot be used as substitutes for the primary angiographic measure.

Unadjusted secondary results carry less weight as confirmatory evidence when multiple outcomes are examined. In general, the more comparisons considered, the greater the chance that some appear notable by chance alone if no multiplicity approach is used. The registry does not report a testing hierarchy, adjustment for multiple comparisons, or a complete statistical analysis plan. The posted secondary comparisons should therefore be treated as exploratory or descriptive rather than as independent confirmation of a treatment effect.

The registry lists 11 secondary outcomes, but does not report analyses for those outcomes in the analysis listings. Some outcome summaries are posted, while a complete account of methods, missing data, and interpretation is not. The event counts are modest, and estimates based on sparse events can remain uncertain even when the point estimates differ. The broader pattern is therefore one of limited precision rather than a set of decisive secondary findings.

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

• Number of Participants Clinically-driven Target Lesion Revascularization (TLR)
• Number of Participants Composite of Cardiac Death, MI Attributed to the Target Vessel and Clinically Driven Target Lesion Revascularization
• Number of Participants Composite of All-cause Mortality, Any MI and Any Revascularization, Target Vessel Revascularization or Revascularization of Non Target Vessels
• Number of Participants Stent Thrombosis
• Number of Participants Acute Success Rates
• Number of Participants In-stent and In-segment Angiographic Binary Restenosis Rate
• In-stent and In-segment Minimum Lumen Diameter
• In-segment Late Lumen Loss

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous: each participant contributes a measured quantity in millimeters, and the reported arm summaries are means and standard deviations. A mean difference compares the average measurement in one arm with the average in the other. Here the reported comparison is Medtronic minus Svelte, giving an estimate of 0.04 mm. The direction of a mean difference depends on which arm is subtracted from which, so the arm means should be read alongside the comparison estimate.

What does a standard deviation describe?

In general, a standard deviation describes the spread of individual measurements around an arm mean. It is not a confidence interval and is not the standard error of the mean difference. The registry reports standard deviations of 0.31 mm for the Svelte arm and 0.27 mm for the Medtronic arm. Those values indicate that individual measurements vary around their respective means; they do not, on their own, show whether the arm means differ beyond sampling uncertainty.

What does the p-value tell the reader?

In general, a p-value measures how incompatible the observed data are with a specified null hypothesis, under the assumptions of the statistical test. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of a difference. The primary unadjusted p-value is 0.458. Read together with the reported confidence interval, it does not provide a statistically clear indication of a difference between the arms under the reported comparison. The registry does not report the complete test specification or confirm whether any adjustment was used in the original analysis.

How should the confidence interval be understood?

In general, a confidence interval gives a range of values that are compatible with the data and the method used to calculate the interval. It conveys uncertainty in the estimated mean difference. The primary interval crosses zero, the value corresponding to no mean difference. It also extends to values on either side of zero. That pattern means the data do not pin down the direction or size of a difference with high precision. A confidence interval is not a range containing a fixed proportion of individual participant measurements; those measurements are described by the arm standard deviations.

What does randomization contribute?

In general, random assignment aims to make treatment groups comparable, on average, with respect to factors that could affect outcomes. It supports a causal comparison when allocation, follow-up, outcome measurement, and analysis are carried out appropriately. The registry identifies the study as randomized and parallel-group, but it does not report the randomization method, concealment procedures, or the handling of participants after assignment. The absence of those details in the registry record means the conduct of these safeguards cannot be evaluated from the posted description alone.

Why do denominators matter?

An outcome mean is based on participants with measurements included in that outcome summary. The primary outcome denominators are 89 and 40. Safety summaries use at-risk denominators of 108 and 51, while the registry enrollment is 159. These are distinct counts and should not be treated as interchangeable. In general, differences between denominators can arise for several reasons, but the reason in this study is not reported in the registry record. Without a stated analysis population and accounting of missing measurements, it is not possible to determine whether the primary outcome summaries include all randomized participants or a selected subset.

Why can event outcomes be less precise?

In general, estimates based on few events often have substantial uncertainty because a small change in the event count can alter the estimated event frequency considerably. The listed secondary outcomes include participant counts and composite events. The registry posts numerical results for several such comparisons, but does not report formal analyses for them. Wide intervals for event comparisons should be read as limited precision, not as evidence that the groups are identical. Continuous measurements and event counts answer different questions and have different sources of uncertainty.

What do unadjusted results mean?

In general, an unadjusted comparison is calculated without accounting for other covariates or for a family of multiple outcome tests. It can be useful as a direct description of the observed groups, but it may not reflect the trial's prespecified primary analysis. The registry labels the available p-values as unadjusted and lists no reported analyses. Details of covariate adjustment, multiplicity control, or sensitivity analyses are not reported in the registry record. The estimates should therefore be understood as the comparisons posted, not as a complete account of every analysis that may have been planned or conducted.

11. Confidence Intervals and Precision

The primary mean difference is estimated as 0.04 mm. Its confidence interval crosses zero and reaches values on both sides of no difference. This interval communicates that the data do not identify a single precise value for the difference. The p-value of 0.458 is consistent with that uncertainty, but the interval is more informative about the range and direction of values compatible with the data.

The confidence interval is wide in relation to the point estimate. It includes a possibility of lower mean loss in either arm, as well as no difference. The result is therefore not precise enough to establish the direction or magnitude of a treatment difference. The registry does not report a threshold for clinical importance, so the clinical significance of the interval's possible values cannot be determined from this record.

The primary outcome analysis includes 89 participants in the Svelte arm and 40 in the Medtronic arm. The imbalance in these posted outcome counts contributes to the context for interpreting the uncertainty, although the registry does not explain why the analysis denominators differ. The standard deviations of 0.31 mm and 0.27 mm describe the spread of measurements within the arms, whereas the confidence interval describes uncertainty in the estimated difference. These are related but distinct quantities.

The secondary event comparisons are also imprecise: their reported intervals include no difference. Smaller event counts limit how sharply the data can distinguish among possible differences. Neither a non-significant result nor an interval spanning zero proves equal outcomes. A more precise estimate would require information that narrows the plausible range; the registry does not provide a formal precision target or margin for this trial.

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 planning figures are illustrative estimates based on the observed effect, not the original trial design. For the primary continuous endpoint, the figures are participants per arm. They use the stated planning assumptions: a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect set to the stated fraction of the observed effect. The trial's own original sample-size assumptions and justification are not reported in the registry record.

The 80% power column describes a planning scenario in which a study of the listed size would have an 80% chance of detecting the assumed effect under the specified assumptions. The 90% power column describes the corresponding scenario for a 90% chance. These are prospective planning illustrations, not guarantees that a study will detect an effect or that a particular result is likely. They are not observed power.

For the primary endpoint, planning for 100% of the observed effect gives 873 participants per arm for 80% power and 1,169 participants per arm for 90% power. Planning for 75% of the observed effect gives 1,552 participants per arm for 80% power and 2,078 participants per arm for 90% power. Planning for 50% of the observed effect gives 3,492 participants per arm for 80% power and 4,675 participants per arm for 90% power. The pattern reflects a general statistical principle: smaller effects are harder to distinguish from random variation and therefore require more participants under otherwise unchanged assumptions.

These planning values should not be read as a judgment about the adequacy of the completed trial, because they are based on the observed effect rather than on a documented original target. They can be especially unstable when the observed estimate is uncertain. For binary outcomes, the illustrative planning calculations likewise report participants per arm; the total-events convention applies to time-to-event outcomes, and no such time-to-event planning result is included in the posted comparisons. The planning values are conditional on the stated assumptions and do not account for design features not specified in those assumptions.

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 = 0.040; pooled standard deviation σ = 0.298.
2. n = 2 × (1.96 + 0.842)² × 0.298² / 0.040² = 872.9, rounded up to 873 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 <- 0.04                      # observed difference in means
sigma <- 0.29828776466892                     # 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(1788150)
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 = 873 (80% power), 1,169 (90% power)
 75% of observed effect: n per arm = 1,552 (80% power), 2,078 (90% power)
 50% of observed effect: n per arm = 3,492 (80% power), 4,675 (90% power)
power.t.test: 873.9 
Simulated power at n = 873 per arm: 0.805 (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. Multiplicity, Missing Data and Analysis Populations

The registry record does not report how multiplicity was handled. Multiple secondary endpoints are listed, including clinical events, composites, and angiographic measures. When many outcomes are examined, unadjusted tests can produce apparently notable results by chance. In general, a prespecified testing hierarchy or other multiplicity procedure can help control that risk. No such procedure or hierarchy is reported in the registry record, so the secondary p-values should not be read as if they were protected against multiple testing.

The registry describes the primary endpoint and its timeframe, but does not report a detailed statistical analysis plan, a full specification of the primary test, or a rationale for selecting the reported analysis population. The posted primary denominators are 89 and 40, while the total enrollment is 159 and the safety denominators are 108 and 51. The record does not explain the differences. The population analyzed for the primary outcome, including whether it was intention-to-treat, per-protocol, or another defined population, is not reported in the registry record.

Missing outcome data and their handling are also not described. The record does not state how many participants lacked an angiographic measurement, why measurements were absent, whether any imputation was used, or whether sensitivity analyses were performed. In general, missingness can affect an estimate if participants with observed outcomes differ systematically from those without observed outcomes. Without an accounting of missing data, the potential impact cannot be evaluated.

The registry lists no reported analyses, and it does not provide details of interim analyses, covariate adjustment, or sensitivity analyses. Their use or absence is not reported in the registry record. These gaps limit the ability to assess whether the posted summaries follow a prespecified plan and how robust the estimates are to alternative assumptions. They do not justify assuming that any particular method was or was not used beyond what the record explicitly states.

15. Safety Results

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

Deaths

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

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: local infection (3.9%), arrhythmia (2.0%), fainting/syncope/vasovagal reaction (2.0%), arthritis (2.0%), renal failure/insufficiency (2.0%).

The safety record reports serious adverse events among 21 of 108 participants at risk in the Svelte arm and 8 of 51 participants at risk in the Medtronic arm. Other adverse events are reported for 36 of 108 and 14 of 51 participants, respectively. The registry lists zero deaths in each arm. These counts use safety denominators and should not be confused with the primary-outcome analysis counts.

The listed serious adverse event terms include Local Infection at 3.9%, and Arrhythmia, Fainting/Syncope/Vasovagal Reaction, Arthritis, Renal Failure/Insufficiency, and Atypical Chest Pain at 2.0% each. The registry does not provide enough detail in the listed summary to determine whether participants could contribute to more than one term or how the terms were coded. The listed event frequencies do not establish whether an event was caused by the stent.

Safety counts are descriptive. The registry record does not provide a comparative statistical analysis of these adverse event summaries or explain the difference between the safety and primary-outcome denominators. The absence of reported deaths in these summaries does not establish that all possible safety risks were excluded.

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

The posted primary results describe the average angiographic in-stent late lumen loss in participants with available outcome data at 6 months post-procedure. The arm means were 0.09 mm for the Svelte stent and 0.13 mm for the Medtronic stent. The estimated mean difference was 0.04 mm, with an unadjusted p-value of 0.458 and a confidence interval that includes no difference. The data therefore do not provide a statistically clear distinction between the two group means in this outcome.

That finding does not demonstrate that the stents are equivalent, that their effects are identical, or that either is non-inferior. Such conclusions require a prespecified margin and an analysis designed to test it. No equivalence or non-inferiority margin is reported in the registry record. A result that does not show a clear difference can reflect uncertainty as well as a small true difference, and the posted interval includes values on both sides of no difference.

The endpoint is an angiographic measurement, not a complete summary of patient experience or clinical outcomes. The study also lists secondary clinical outcomes, but the available secondary comparisons do not resolve the uncertainty in the primary estimate. The registry does not provide a detailed account of missing outcome data, analysis populations, or multiplicity procedures. These omissions limit the conclusions that can be drawn from the posted summaries.

The randomized design supports a direct comparison between the assigned groups, but interpretation still depends on how participants were followed and analyzed. The registry does not report enough detail to assess those features fully. The findings apply to the study population and the stated follow-up measures; they do not establish results for other populations, other devices, other follow-up periods, or other clinical questions. The results should be understood as estimates with uncertainty, not as medical advice or a recommendation about device choice.

17. Why This Trial Matters Statistically

This trial illustrates a central issue in interpreting randomized comparisons: the point estimate alone does not determine how conclusive a result is. The primary means differ numerically, but the confidence interval crosses zero and the unadjusted p-value is 0.458. The interval indicates uncertainty about both the direction and size of the difference. Statistical interpretation therefore requires reading the estimate together with its precision rather than treating the p-value as a complete summary.

The study also illustrates the distinction between a continuous surrogate-like measurement and clinical events. Late lumen loss describes an angiographic feature of the treated segment, while outcomes such as revascularization and composites describe participant events. They are related to different questions and should not be collapsed into a single claim. The registry's secondary outcomes add context, but their estimates are imprecise and no multiplicity approach is reported.

Denominators are another important statistical detail. Enrollment, primary-outcome sample sizes, and safety populations are not the same counts in the registry record. Without a participant accounting or analysis-population definition, readers cannot determine why the denominators differ or how missing observations may affect the findings. This matters because an estimate depends on which participants contribute data.

Finally, the planning illustrations show how strongly sample-size calculations depend on the effect selected for detection. Smaller assumed effects lead to larger planning requirements under the stated assumptions. Since the registry does not report the original design assumptions, these retrospective illustrations cannot establish whether the completed study met its intended design target. Together, these features make the trial a useful example of why estimates, uncertainty, populations, and analysis plans all matter when reading clinical trial results.

18. 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.

Several trial-specific limitations affect interpretation. The primary analysis denominators are 89 for the Svelte arm and 40 for the Medtronic arm, while the safety summaries use 108 and 51 at risk and the registry lists enrollment of 159. The record does not reconcile these counts. It also does not describe missing angiographic measurements, the reasons for different denominators, or the analysis population. As a result, the representativeness of the primary outcome summaries cannot be assessed from the registry entry alone.

The trial was unmasked. That is relevant context for interpreting the study, although the primary outcome is an angiographic measurement. The registry does not state whether outcome assessors were masked or how image measurement was standardized. Randomization procedures and allocation concealment are also not described. The record says the study was multicenter but does not state how many centers participated.

The posted comparison has limited precision, and the registry does not report a clinically meaningful difference threshold. The study's original sample-size assumptions, interim analyses, analysis model, and detailed statistical plan are not reported in the registry record. No multiplicity strategy is reported for the numerous secondary outcomes. The numerical secondary results therefore do not provide a firm basis for confirmatory conclusions.

Follow-up information is limited to the specified outcome timeframes, including the 6-month primary angiographic endpoint and listed 1-year secondary event outcomes. The registry does not supply a full account of follow-up completeness or later outcomes. The trial compares these two stent systems in the stated population and does not establish conclusions for other devices, populations, or clinical settings.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Safety and Efficacy Study of the Svelte Drug-Eluting Coronary Stent Delivery System — NCT01788150.
• Registry record last updated 2021-05-04; status last verified 2021-04.
• Results first posted 2021-05-04.
• 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.

22. Record Summary

NCT01788150 is a completed randomized, open-label, parallel-group study comparing the Svelte Drug-Eluting Coronary Stent with the Medtronic Resolute Integrity Drug-Eluting Stent. The registry lists enrollment of 159, a start date of 2013-01, and primary completion in 2014-05. The study was described as prospective, active-control, and multicenter.

The primary outcome was mean angiographic in-stent late lumen loss at 6 months post-procedure. The reported means were 0.09 mm and 0.13 mm, with a mean difference of 0.04 mm and an unadjusted p-value of 0.458. The confidence interval includes no difference. The registry also lists clinical and angiographic secondary outcomes and safety summaries. Important details about analysis populations, missing data, multiplicity, and the original sample-size design are not reported in the registry record.