Unreported exclusion and sampling bias in interpretation of randomized controlled trials in patients with STEMI

Aims: To assess the impact of sampling bias due to reported as well as unreported exclusion of the target population in a multi-center randomized controlled trial (RCT)of ST-elevation myocardial infarction (STEMI). Methods and Results: We compared clinical characteristics and mortality between participants in the DANAMI-3 trial to contemporary non-participants with STEMI using unselected registries. A total of 179 DANAMI-3 participants (8%)and 617 contemporary non-participants (22%)had died (Log-Rank: P < 0.001)after a median follow-up of 1333 days (range: 1–2021 days). In an unadjusted Cox regression model all groups of non-participants had a higher hazard ratio to predict mortality compared to participants: eligible excluded (n = 144)(hazard ratio: 3.41 (95% CI: (2.69–4.32)), ineligible excluded (n = 472)(hazard ratio: 3.42 (95% CI: (2.44–4.80), eligible non-screened (n = 154)(hazard ratio: 3.37 (95% CI: (2.36–4.82)), ineligible non-screened (n = 154)(hazard ratio: 6.48 (95% CI: (4.77–8.80). Conclusion: Sampling bias had occurred due to both reported and unreported exclusion of eligible patients and the difference in mortality between participants and non-participants could not be explained only by the trial exclusion criteria. Thus, screening logs may not be suited to address the risks of sampling bias

Bleeding Events After ST-segment Elevation Myocardial Infarction in Patients Randomized to an All-comer Clinical Trial Compared With Unselected Patients

Most studies reporting bleedings in patients with ST-segment elevation myocardial infarction (STEMI) are reports from clinical trials, which may be unrepresentative of incidences in real-life. In this study, we investigated 1-year bleeding and mortality incidences in an unselected STEMI population, and compared participants with nonparticipants of a randomized all-comer clinical trial (The Third DANish Study of Optimal Acute Treatment of Patients with STEMI (DANAMI-3)). Hospital charts were read and bleedings classified according to thrombolysis in myocardial infarction (TIMI) and Bleeding Academic Research Consortium (BARC) criteria in 2,490 consecutive STEMI patients who underwent primary percutaneous coronary intervention in a single, large, and tertiary heart center. Thrombolysis in myocardial infarction minor and/or major bleeding (TMMB) occurred in 4.4% day 0 to 30 and 2.1% day 31 to 365. DANAMI-3 nonparticipants (n = 887) had significantly higher 30-day bleeding rates than DANAMI-3-participants (n = 1,603) (7.2% vs 2.9%, p 2 and anemia. Patients with cardiac arrest, Killip-class>2, and anemia accounted for 70.0% of 30-day TMMBs, and the majority of these patients were DANAMI-3 nonparticipants. TMMB day 0 to 30 was associated with increased 30-day mortality (hazard ratio 3.1, 95% confidence interval 1.9 to 5.2, p 2 were accountable for a high rate of TMMBs. Bleeding incidences from clinical trials cannot be translated to an unselected STEMI population

Comparison between patients included in randomized controlled trials of ischemic heart disease and real-world data. A nationwide study

Background: The objective was to compare patients with ischemic heart disease (IHD) undergoing percutaneous coronary intervention (PCI) who were included in randomized controlled trials (RCTs) (trial participants) with patients who were not included (nonparticipants) on a trial-by-trial basis and according to indication for PCI. Methods: In this cohort study, we compared patients with IHD who were randomized in RCTs in relation to undergoing PCI in Denmark between 2011 and 2015 were considered as RCT-participants in this study. The RCT-participants were compared with contemporary nonparticipants with IHD undergoing PCI in the same period, and they were identified using unselected national registry data. The primary end point was all-cause mortality. Results: A total of 10,317 (30%) patients were included in 10 relevant RCTs (trial participants), and a total of 23,644 (70%) contemporary patients did not participate (nonparticipants). In all the included RCTs, nonparticipants had higher hazard ratios for mortality compared to trial participants (P <.001). Among all patients treated with PCI, the pooled estimates showed a significantly higher mortality rate for nonparticipants compared to trial participants (hazard ratio: 2.03, 95% CI: 1.88-2.19) (P <.001). When patients were stratified according to indication for PCI, the pooled estimates showed a significantly lower mortality rate for trial participants compared to nonparticipants in all strata (P for all <.001). Conclusions: Trial participants in recently performed RCTs including patients undergoing PCI were not representative of the general population of patients with IHD treated with PCI according to clinical characteristics and mortality. The difference in mortality was found irrespective of the indication for PCI. Thus, results from RCTs including patients undergoing PCI should be extrapolated with caution to the general patient population