This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Attain Performa(TM) Quadripolar Lead Study (NCT01751022), a na na study. The primary outcome is Lead Complication-free Rate at 6 Months.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01751022 |
| Phase | NA |
| Condition | Heart Failure |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 1202 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Medtronic Cardiac Rhythm and Heart Failure |
| Results posted | Yes |
2. Clinical Question
The study asks whether subjects receiving an Attain Performa left-ventricular lead remain free of lead-related complications through 6 months after implant. The registry evaluates Models 4298, 4398, and 4598 separately. Its stated population for the primary endpoint is subjects with an attempted Attain Performa LV Lead Model.
Population
Subjects with an attempted Attain Performa LV lead. The registry describes results separately for Models 4298, 4398, and 4598.
Intervention
An Attain Performa pacing lead used along with a standard CRT-D system. The study also assesses interactions between the leads and the Medtronic CRT-D system.
Comparator
There is no separate control group. This is a single-group study, and the lead models are evaluated separately rather than as randomized comparison arms.
Primary question
What is the probability of being free from Attain Performa lead-related complications from implant to 6 months, and does the lower confidence bound meet the stated safety criterion?
The primary safety objective is framed as a probability, with a 97.5% confidence interval. For Models 4298 and 4398, the registry says the lead would be considered safe if the probability of being free from lead-related complications at 6 months were greater than 87%, requiring the one-sided 97.5% lower confidence bound to exceed 87%. The description for Model 4598 says its safety performance would be characterized by summarizing that probability. The registry narrative later says the lower boundaries exceeded the 87% threshold for all models.
This is a safety and device-performance question, not a comparison of the leads against an untreated group or another lead. Secondary outcomes include implant success, lead handling, pacing measurements, implant-related times, and complications. The registry record does not report the detailed estimates for those outcomes.
3. Trial Design
NCT01751022 is listed as a completed, single-group device study sponsored by Medtronic Cardiac Rhythm and Heart Failure. The registry lists enrollment as 1202 and the condition as heart failure. The study began in 2012-12, with primary completion in 2015-02. Phase is listed as NA. Allocation is listed as NA and masking as NONE.
The intervention is an Attain Performa pacing lead used with a standard CRT-D system. Three lead models are named: 4298, 4398, and 4598. The registry describes the study as a single-arm study with separate analysis for each lead model. Thus, the model-specific groups are not randomized arms and should not be read as a like-for-like controlled comparison. Differences between their results, if reported, could not be attributed to model alone on the basis of this design.
The primary endpoint covers the period from implant to 6 months post-implant and measures the probability of remaining free from lead-related complications. The secondary outcome list includes the presence of PNS across LV lead pacing polarities, successful implant by lead model, acceptable lead handling, pacing capture thresholds, implant-related times, pacing impedance, and individual lead-related complication rates.
The registry record identifies source reports for some model results in its primary endpoint description, but the full population description is cut off in the available record. Further details about recruitment, eligibility, site procedures, follow-up completeness, and how subjects were assigned to a particular lead model are not reported in the registry record. A formal statistical analysis plan is not reported in the registry record. The record lists 9 outcome measures and 0 analyses; the latter does not establish that no analyses were conducted, only that none are listed in the registry results fields.
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.
Before assignment: Out of the 1202 Intial enrollments; 77 were excluded due to to the following pre-implant events: 1. unsuccessful cannulation (25) 2. death (3) 3. Exit prior to implant attempt (43) 4. Attain Performa Lead implant not attempted (6) Resulting in 1125 subjects with Attain Performa Lead Implant Attempts
Overall Study
| Stage | Model 4298 | Model 4398 | Model 4598 |
|---|---|---|---|
| STARTED | 499 | 326 | 300 |
| COMPLETED | 443 | 282 | 273 |
| NOT COMPLETED | 56 | 44 | 27 |
Analysis population for the primary outcome, as defined in the registry: Subjects with an attempted Attain Performa LV Lead Model. Results for lead model 4298 comes from its PMA-S Clinical Report Version 1, 27MAR2014; results for lead model 4398 comes from its PMA-S Clinical Report Version 3, 03SEP2014; results for lead model 4598 comes from its PMA-S Clinical Report Version 1, 29AUG2014.
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.
Population: Subjects with an attempted Attain Performa LV Lead implant
| Characteristic | Unit | Attain Performa LV Lead Model 4298 | Attain Performa LV Lead Model 4398 | Attain Performa LV Lead Model 4598 | Total |
|---|---|---|---|---|---|
| Participants analysed | 499 | 326 | 300 | 1125 | |
| Age, Continuous | years | 68 (SD 11) | 66 (SD 11) | 67 (SD 11) | 67 (SD 11) |
| Sex: Female, Male: Female | Participants | 143 | 93 | 93 | 329 |
| Sex: Female, Male: Male | Participants | 356 | 233 | 207 | 796 |
| Race/Ethnicity, Customized: Subject/physician chose not to provide information | participants | 14 | 9 | 5 | 28 |
| Race/Ethnicity, Customized: Not reportable per local laws or regulations | participants | 30 | 21 | 48 | 99 |
| Race/Ethnicity, Customized: American Indian or Alaska Native | participants | 4 | 0 | 5 | 9 |
| Race/Ethnicity, Customized: Asian | participants | 7 | 8 | 17 | 32 |
| Race/Ethnicity, Customized: Black or African American | participants | 38 | 21 | 17 | 76 |
| Race/Ethnicity, Customized: Hispanic or Latino | participants | 18 | 11 | 11 | 40 |
| Race/Ethnicity, Customized: Native Hawaiian or Pacific Islander | participants | 0 | 1 | 0 | 1 |
| Race/Ethnicity, Customized: White or Caucasian | participants | 387 | 252 | 197 | 836 |
| Race/Ethnicity, Customized: Two or more races | participants | 1 | 3 | 0 | 4 |
| Region of Enrollment: United States | participants | 360 | 249 | 152 | 761 |
| Region of Enrollment: Malaysia | participants | 0 | 1 | 1 | 2 |
| Region of Enrollment: Greece | participants | 0 | 1 | 0 | 1 |
| Region of Enrollment: Saudi Arabia | participants | 9 | 6 | 2 | 17 |
| Region of Enrollment: Austria | participants | 8 | 0 | 2 | 10 |
| Region of Enrollment: Netherlands | participants | 13 | 1 | 9 | 23 |
| Region of Enrollment: Slovakia | participants | 4 | 2 | 7 | 13 |
| Region of Enrollment: Slovenia | participants | 0 | 5 | 3 | 8 |
| Region of Enrollment: Chile | participants | 12 | 0 | 0 | 12 |
| Region of Enrollment: France | participants | 0 | 2 | 8 | 10 |
| New York Heart Association Classification (NYHA): I | participants | 8 | 4 | 4 | 16 |
| New York Heart Association Classification (NYHA): II | participants | 125 | 94 | 89 | 308 |
| New York Heart Association Classification (NYHA): III | participants | 352 | 216 | 198 | 766 |
| New York Heart Association Classification (NYHA): IV | participants | 14 | 12 | 9 | 35 |
| Left Ventricular Ejection Fraction (LVEF) | % | 25 (SD 7) | 26 (SD 7) | 27 (SD 7) | 26 (SD 7) |
| QRS (Electrocardiogram Complex) | ms | 155 (SD 23) | 156 (SD 24) | 156 (SD 23) | 156 (SD 23) |
6. Primary Endpoint
The registry lists the primary outcome as Lead Complication-free Rate at 6 Months, measured over Implant to 6 months post-implant.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 97.5% Confidence Interval |
| Unit | Survival Probability (%) |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the lead complication-free rate at 6 months, expressed as a survival probability. It concerns whether subjects are free from Attain Performa lead-related complications over the period from implant to 6 months post-implant. The population is described as subjects with an attempted Attain Performa LV lead, with results evaluated separately for Models 4298, 4398, and 4598.
A complication-free probability is useful for a device safety question because it summarizes the proportion of the target population remaining without the specified lead-related event through a defined follow-up period. The registry calls the measure a survival probability; this terminology does not imply that the endpoint is death. The endpoint description focuses on freedom from lead-related complications, and death counts are not reported in the adverse-event summary.
The registry specifies a 97.5% confidence interval. For Models 4298 and 4398, the stated criterion is that the one-sided 97.5% lower confidence bound exceed 87%. A lower bound is the conservative edge of the interval and represents uncertainty around the estimated probability. The registry narrative says the lower boundaries exceeded 87% for all three models and concludes that the criterion was met. It does not report the model-specific probabilities or the confidence-bound values, so their numerical distance from the threshold and their precision cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry’s primary endpoint narrative reports that the lower boundaries of the 97.5% confidence intervals exceeded the 87% threshold for all lead models. It states that the criterion was met for all models. This is the principal reported conclusion about the primary safety objective. The result is stated qualitatively: the record does not give the estimated complication-free probabilities, the lower confidence bounds, the upper bounds, or model-specific event counts for the primary endpoint.
That absence matters for interpretation. A threshold statement indicates whether the specified bound crossed the criterion, but it does not show how far the bound lay above 87%, nor how narrow or wide the interval was. Without estimates and interval limits, readers cannot judge the degree of precision or compare the magnitude of the estimates across models. The registry does not report p-values for this endpoint.
The endpoint is evaluated separately for Models 4298, 4398, and 4598. The record uses different wording for the model objectives: Models 4298 and 4398 have an explicit criterion requiring the lower bound to exceed 87%, while the safety performance of Model 4598 is described as being characterized by summarizing the complication-free probability. The overall narrative then says the lower boundaries for all models exceeded 87% and that the criteria were met. Those statements should be read as the registry’s reported conclusion, while recognizing that the detailed model-specific values are absent.
This study has no separate control group. Its results therefore describe outcomes among subjects receiving the studied leads and CRT-D system, rather than estimating a treatment contrast against another device or an untreated group. The three lead-model results are also not randomized comparisons. Differences between models, if any, could reflect differences in the groups or other factors, and cannot be interpreted as causal model effects from this design alone.
The registry lists adverse-event counts by lead model: serious adverse events affected 218 of 499 at risk for Model 4298, 134 of 326 for Model 4398, and 117 of 300 for Model 4598. Other adverse events affected 155 of 499, 84 of 326, and 84 of 300, respectively. These are adverse-event summaries, not the primary lead complication-free endpoint; the registry does not define them as interchangeable. Serious-event terms listed with percentages include decompensated heart failure at 11.4%, atrial fibrillation at 3.7%, and lead dislodgement at 3.2%. The record does not specify the denominator for those term percentages in the material reported.
9. Statistical Methods Explained
The primary outcome is expressed as a survival probability over a stated follow-up period. In general, a survival probability describes the chance of remaining free from a specified event up to a particular time. Here the event of interest is an Attain Performa lead-related complication, and the period runs from implant to 6 months post-implant. The use of “survival” in the endpoint name does not mean that this is a mortality endpoint.
The registry gives a 97.5% confidence interval for the probability. In general, a confidence interval communicates uncertainty around an estimate: narrower intervals indicate greater precision, while wider intervals indicate less precision. A lower confidence bound is the lower edge of the interval. The stated safety criterion for Models 4298 and 4398 is that the one-sided 97.5% lower bound be greater than 87%. The registry’s narrative says the lower boundaries exceeded that threshold for all models, but the actual estimates and bounds are not reported in the registry record. Consequently, the precision and margin relative to the criterion cannot be inspected.
The endpoint description indicates that models are analyzed separately. Separate summaries are appropriate to the stated model-specific safety objectives, but they do not create a randomized comparison between models. A comparison of estimates from separate groups would be descriptive unless supported by an appropriate comparative design and analysis. Allocation is listed as NA, and the study is classified as single-group. No control-group contrast should therefore be inferred.
The primary endpoint is called a survival probability, but the registry record does not specify the estimator, handling of censoring, or the exact event-counting rules. In general, time-to-event methods can account for differing follow-up when event times and censoring information are available. If all subjects had complete follow-up, a simpler proportion could be used, but follow-up completeness and the calculation method are not reported. It is therefore not possible to identify the precise estimator from the registry record.
The registry also lists multiple secondary outcomes: PNS across pacing polarities, implant success, lead handling, capture thresholds, implant-related times, impedance, and individual lead-related complications. These outcomes address different aspects of device performance and should not be treated as substitutes for the primary safety endpoint. The record lists 9 outcome measures, but does not provide analyses for those outcomes in the results information. It also does not report whether secondary outcomes were prespecified as confirmatory or exploratory.
Multiplicity is a general concern when several outcomes, groups, or analyses are examined: the chance of finding at least one apparently notable result can increase as the number of statistical tests increases. Whether and how that issue was addressed for this study is not reported in the registry record. The stated 97.5% interval for the primary endpoint does not, by itself, reveal how the analysis handled multiple lead models or secondary outcomes.
Over-dispersion is a general concept for count data in which the observed variability exceeds what a simple count model assumes. It can affect standard errors and confidence intervals if a model does not allow for that extra variability. The primary endpoint is a probability rather than a reported count-model estimate, and the registry does not identify a count model or report over-dispersion diagnostics. No conclusion about such diagnostics can be drawn.
The registry record does not report a sample-size justification, target precision, or a statistical analysis plan. It also does not describe interim analyses, stopping rules, adjustment methods, missing-data procedures, or a detailed analysis population beyond the stated attempted-lead population for the primary endpoint. These omissions prevent a full assessment of how the analysis was planned and how deviations from the intended follow-up, if any, were handled.
The sample-size assumptions associated with the study’s planning illustration describe a generic calculation based on an observed effect, two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. They say the effect to detect is a stated fraction of the observed effect; time-to-event illustrations use total events, while other illustrations use participants per arm. These assumptions are not the study’s own design justification. In particular, a planning illustration is not an observed-power calculation and cannot establish the achieved precision of the single-group primary endpoint.
For general interpretation, estimates and confidence intervals are more informative than a threshold conclusion alone: they show both the estimated outcome and its uncertainty. Since the registry narrative reports only that the lower bounds crossed the threshold, readers can state the recorded conclusion but cannot reconstruct or independently verify the model-specific statistical results from the numerical information available in the record.
10. Multiplicity, Missing Data and Analysis Populations
The registry names three lead models and a range of secondary outcomes, but the record does not describe a multiplicity strategy. It is not reported in the registry record whether the primary endpoint was tested separately for each model under a prespecified family-wise plan, whether adjustments were made, or whether secondary outcomes were treated as descriptive. This limits interpretation of the collection of results: when several endpoints or groups are examined, chance findings can accumulate unless the analysis plan addresses that issue. The threshold statement for the primary outcome should not be taken as evidence that multiplicity was or was not controlled.
Missing-data handling is not reported in the registry record. The record does not state how incomplete follow-up, withdrawals, loss to follow-up, or unavailable endpoint assessments were treated. Nor does it give the number of subjects with complete primary endpoint follow-up or describe sensitivity analyses. For a 6-month complication-free probability, incomplete observation can affect the estimate depending on how follow-up ends and how censoring is handled. Without these details, the potential influence of missing observations cannot be assessed.
The primary endpoint population is described as subjects with an attempted lead model. The record does not provide a fuller definition of the analysis population or say whether any subjects were excluded after an attempted implant. It also does not report whether all enrolled subjects entered a model-specific endpoint analysis. The registry lists adverse-event groups with 499, 326, and 300 subjects at risk, but those denominators should not automatically be treated as primary endpoint analysis populations because the record does not explicitly equate them.
Interim analyses, stopping rules, and changes to the analysis plan are not reported in the registry record. The record lists 0 analyses in its results information, which means the registry does not list analysis entries there; it does not demonstrate that analyses were not performed. These reporting gaps leave important aspects of analysis conduct and population selection unresolved.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Attain Performa LV Lead Model 4298 | 218 | 499 | 43.7% |
| Attain Performa LV Lead Model 4398 | 134 | 326 | 41.1% |
| Attain Performa LV Lead Model 4598 | 117 | 300 | 39.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Attain Performa LV Lead Model 4298 | 155 of 499 |
| Attain Performa LV Lead Model 4398 | 84 of 326 |
| Attain Performa LV Lead Model 4598 | 84 of 300 |
Most frequent serious adverse event terms
| Event term | Organ system | Attain Performa LV Lead Model 4298 | Attain Performa LV Lead Model 4398 | Attain Performa LV Lead Model 4598 |
|---|---|---|---|---|
| Decompensated heart failure | Cardiac disorders | 57 of 499 | 30 of 326 | 33 of 300 |
| Atrial fibrillation | Cardiac disorders | 16 of 499 | 12 of 326 | 3 of 300 |
| Lead dislodgement | General disorders | 16 of 499 | 3 of 326 | 8 of 300 |
| Pneumonia | Infections and infestations | 7 of 499 | 8 of 326 | 9 of 300 |
| Chest pain | General disorders | 10 of 499 | 7 of 326 | 3 of 300 |
| Ventricular tachycardia | Cardiac disorders | 4 of 499 | 1 of 326 | 7 of 300 |
| Pneumothorax | Respiratory, thoracic and mediastinal disorders | 5 of 499 | 3 of 326 | 4 of 300 |
| Atrial flutter | Cardiac disorders | 4 of 499 | 5 of 326 | 2 of 300 |
| GI bleed | Gastrointestinal disorders | 7 of 499 | 2 of 326 | 2 of 300 |
| Syncope | Nervous system disorders | 6 of 499 | 2 of 326 | 3 of 300 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Attain Performa LV Lead Model 4298 | Attain Performa LV Lead Model 4398 | Attain Performa LV Lead Model 4598 |
|---|---|---|---|---|
| Decompensated heart failure | Cardiac disorders | 31 of 499 | 18 of 326 | 14 of 300 |
| Inappropriate phrenic nerve stimulation | General disorders | 18 of 499 | 23 of 326 | 18 of 300 |
| Inappropriate stimulation of diaphragm | General disorders | 21 of 499 | 13 of 326 | 8 of 300 |
| Atrial fibrillation | Cardiac disorders | 12 of 499 | 3 of 326 | 12 of 300 |
| Implant site hematoma | General disorders | 11 of 499 | 5 of 326 | 0 of 300 |
| Implant site pain | General disorders | 7 of 499 | 4 of 326 | 5 of 300 |
| Chest pain | General disorders | 8 of 499 | 3 of 326 | 4 of 300 |
| Hypotension | Vascular disorders | 11 of 499 | 2 of 326 | 1 of 300 |
| Ventricular tachycardia | Cardiac disorders | 8 of 499 | 2 of 326 | 3 of 300 |
| Hypertension | Vascular disorders | 6 of 499 | 0 of 326 | 4 of 300 |
Serious events with the highest arm-level rate: decompensated heart failure (11.4%), atrial fibrillation (3.7%), lead dislodgement (3.2%), pneumonia (3.0%), ventricular tachycardia (2.3%).
The adverse-event summary separates serious and other adverse events by lead model. For Model 4298, 218 subjects were affected by serious adverse events among 499 at risk, and 155 were affected by other adverse events among 499 at risk. For Model 4398, the corresponding counts are 134 of 326 and 84 of 326. For Model 4598, they are 117 of 300 and 84 of 300. These counts describe the adverse-event groups in the registry; they are not the primary endpoint estimates.
The listed serious-event terms and percentages are decompensated heart failure, 11.4%; atrial fibrillation, 3.7%; lead dislodgement, 3.2%; pneumonia, 3.0%; ventricular tachycardia, 2.3%; and chest pain, 2.1%. The registry does not report the denominator or model-specific breakdown for these percentages in the available record. The terms should therefore be read as the listed serious adverse events, not as model-specific rates or as evidence that the lead caused each event.
The record does not report deaths in these adverse-event groups. Serious and other adverse events can include events that are not lead-related, and the summary does not establish causal attribution. The primary endpoint is specifically freedom from lead-related complications, so adverse-event counts should not be substituted for its complication-free probability.
12. What the Result Does, and Does Not, Mean
The registry’s reported primary conclusion is that the lower boundaries of the 97.5% confidence intervals exceeded 87% for all three lead models, and that the criterion was met. This supports a precise description of what the record states about its prespecified safety threshold. The numerical bounds and complication-free probability estimates are not reported, however, so the size and precision of the results cannot be independently judged from the record.
The result does not establish that one lead model is safer than another. The study is single-group, with separate model analyses and no randomized control group. It does not estimate a contrast against another lead or against no lead. Nor does the reported threshold conclusion establish that the lead caused or prevented every event listed in the adverse-event summary. The registry does not provide causal attribution for those events.
The result is specific to the primary endpoint as described: freedom from lead-related complications from implant to 6 months. It does not by itself answer every question about long-term device performance, other complications, pacing measures, or quality of life. Secondary outcomes are named, but their numerical analyses are not included in the registry results information. The period after 6 months is outside the stated primary endpoint timeframe.
Interpretation is also constrained by reporting gaps. The registry does not give the model-specific primary endpoint counts, estimates, confidence limits, methods for censoring, missing-data handling, or analysis-population details. It does not report a statistical analysis plan or a multiplicity strategy. Those omissions do not negate the registry’s stated conclusion, but they limit assessment of how robustly and precisely the result was estimated.
In short, the available record reports that the threshold was crossed for each model, while leaving the underlying numerical estimates and important analysis details unavailable. That is a narrower claim than a comparative treatment effect or a complete account of device safety.
13. Why This Trial Matters Statistically
This trial illustrates how a single-group device study can frame safety around an absolute performance threshold rather than a treatment contrast. The primary question is whether a lead-specific complication-free probability meets a prespecified benchmark. This differs from asking whether an intervention performs better than a control: there is no separate control group, and the three lead models are analyzed separately.
The use of a confidence bound makes uncertainty central to the decision rule. A point estimate alone would not show how precisely the probability was estimated; the lower confidence bound provides a conservative comparison with the 87% benchmark stated for Models 4298 and 4398. The registry reports that the bounds exceeded the threshold for all models, but does not report the numerical limits. This makes the threshold conclusion visible while leaving its degree of precision opaque.
The study also shows why endpoint definitions and analysis populations matter. The primary outcome concerns freedom from lead-related complications through 6 months among subjects with an attempted lead. Adverse-event summaries use separate group counts and do not automatically represent the same endpoint or population. Keeping these measures distinct avoids treating general adverse events as equivalent to the endpoint’s specified lead-related complications.
Finally, statistical interpretation depends on transparent reporting of estimates, uncertainty, missing-data handling, and the analysis plan. The registry includes an overall conclusion and a list of secondary outcomes, but not the detailed primary estimates or analysis methods needed to evaluate the full evidence trail. This is an important distinction between a reported decision against a benchmark and the broader statistical information needed to assess precision, assumptions, and generalizability.
14. 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 main limitation for statistical interpretation is that the registry does not report model-specific primary endpoint estimates or confidence-bound values. Although it says the lower boundaries exceeded 87% for all models, readers cannot determine the distance above the threshold or compare precision across models. Primary endpoint event counts are also not reported in the available record.
The design is single-group, with no randomized control arm. Results describe outcomes among subjects receiving the studied leads and CRT-D system; they do not estimate a comparative effect. Separate model results are not randomized head-to-head comparisons, so any apparent differences cannot be attributed to lead model alone using this record.
The record does not report the estimator, censoring rules, follow-up completeness, missing-data methods, analysis population details, or sensitivity analyses. It does not provide a statistical analysis plan, sample-size justification, multiplicity handling, interim-analysis information, or stopping rules. These omissions limit assessment of the assumptions and procedures behind the reported threshold conclusion.
Adverse-event summaries are not a substitute for the primary endpoint. Their denominators and affected-subject counts are reported by model, but the record does not specify the denominator for the listed serious-event term percentages or provide causal attribution. Death counts are not reported. The adverse-event summaries therefore offer limited context for interpreting the primary lead-related complication-free outcome.
The primary endpoint is limited to implant through 6 months post-implant. The record does not provide a longer-term primary result. The full description of the primary population is truncated, and the registry’s listed 0 analyses indicates no analysis entries in its results information rather than establishing that no analyses were done.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Attain Performa(TM) Quadripolar Lead Study — NCT01751022.
- Registry record last updated 2016-12-05; status last verified 2016-10.
- Results first posted 2016-12-05.
- 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.
Continue through the Clinical Biostats statistical pathway
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18. Record Summary
NCT01751022 is a completed, single-group study of Attain Performa LV Lead Models 4298, 4398, and 4598, used with a standard CRT-D system. The registry lists enrollment of 1202, heart failure as the condition, and Medtronic Cardiac Rhythm and Heart Failure as sponsor. The study began in 2012-12 and reached primary completion in 2015-02.
The primary endpoint is the lead complication-free rate from implant to 6 months, expressed as a survival probability with a 97.5% confidence interval. The registry says the lower confidence boundaries exceeded 87% for all models and that the criterion was met. It does not report the model-specific estimates or bounds.
The registry lists secondary measures involving PNS, implant success, lead handling, pacing thresholds and impedance, implant-related times, and lead-related complications. Adverse-event counts are reported by model, but detailed primary analyses, missing-data methods, and the statistical analysis plan are not reported in the registry record.