External validity of ST elevation myocardial infarction trials: The Zwolle studies

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 <0.0001), but not thereafter (p = 0.8). DANAMI-3 nonparticipation was significantly associated with 30-day TMMB (hazard ratio, 1.8, 95% confidence interval, 1.2 to 2.8, p = 0.007), but this did not persist after adjusting for resuscitated cardiac arrest, Killip-class>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 <0.0001) but not thereafter (p = 0.9). In conclusion, we found that clinical trial (DANAMI-3) nonparticipants had significantly more TMMBs within 30 days than participants. Patients with resuscitated cardiac arrest, anemia, and Killip-class>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.

A cohort study following up on a randomised controlled trial of a telemedicine application in COPD patients

Introduction

The studies that constitute the knowledge base of evidence based medicine represent only 5%–50% of patients seen in routine clinical practice. Therefore, whether the available evidence applies to the implementation of a particular service often remains unclear. Chronic obstructive pulmonary disease (COPD) is no exception.

Methods

In this article, the effects of implementing a telemedicine intervention for COPD patients were analysed using data collected before, during, and after a randomised controlled trial (RCT). More specifically, regression techniques using robust variance estimators were used to analyse whether the use of telemedicine, patient age, and gender could explain the risk of readmission, length of hospital admission, and death during a five-year observation period.

Results

Increased risk of readmission was significantly related to both use of telemedicine and increased age in three sub-periods of the study, whereas women showed a more pronounced risk of readmission than men only during and after the RCT period. The number of days admitted to hospital was higher for patients using telemedicine and being of older age. Risk of death during the observation period was decreased for patients using telemedicine and for female patients and increased for elderly patients. No interaction between intervention and time period was observed. Statistically significant relationships were identified between use of telemedicine and risk of readmission, days admitted to hospital, and death.

Discussion

Research on effect modification in telemedicine is essential in designing future implementation of interventions as it cannot be taken for granted that effectiveness follows from efficacy.

Impact of diabetes on outcome in patients with non-ST-elevation myocardial infarction

BACKGROUND

Diabetes mellitus contributes to the increase of cardiovascular deaths worldwide. Despite continuous treatment evolution, patients with diabetes suffering from an acute coronary syndrome still have a high morbidity and mortality. We aimed to analyze the impact of diabetes on one-year outcome in an unselected patient population with non-ST-elevation myocardial infarction (non-STEMI).

METHODS

Retrospective analysis of 847 unselected patients with non-STEMI. We compared the baseline characteristics, treatment and outcome of patients versus those without diabetes.

RESULTS

A total of 138 patients had diabetes (16%) and 709 (84%) had no diabetes. Patients with diabetes were older, often had hypertension, hyperlipidemia, previous myocardial infarction and Killip class ≥2 on admission. Approximately 80% of both patients, with and without diabetes, underwent diagnostic coronary angiography. Multivessel disease was more present among patients with diabetes, but patients with diabetes were treated more often conservatively. At one-year follow up rates of death and major adverse cardiac events were significantly higher in patients with diabetes compared to those without diabetes (8% vs. 3%; P=0.001 and 23% vs. 14%; P=0.008, respectively). Even after adjustment for differences in baseline characteristics, diabetes remained an independent predictor of mortality (OR: 2.25; CI95%: 1.05-3.91).

CONCLUSIONS

In an unselected patient population with non-STEMI, patients with diabetes have higher risk factors on admission, less often undergo coronary revascularisation and have worse outcome at one-year follow-up. Diabetes is an independent predictor of one-year mortality in patients with non-STEMI.

Clinical impact of sirolimus-eluting stent in ST-segment elevation myocardial infarction: a meta-analysis of randomized clinical trials

OBJECTIVES

To evaluate outcome of patients undergoing sirolimus-eluting stent (SES) as compared to bare-metal stent (BMS) implantation during primary angioplasty for ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

The role of SES in primary percutaneous coronary intervention setting is still debated.

METHODS

We searched Medline, EMBASE, CENTRAL, scientific session abstracts, and relevant Websites for studies in any language, from the inception of each database until October 2008. Only randomized clinical trials with a mean follow-up period >6 months and sample size >100 patients were included. Primary endpoint for efficacy was target-vessel revascularization (TVR) and primary endpoint for safety was stent thrombosis. Secondary endpoints were cardiac death and recurrent myocardial infarction (MI).

RESULTS

Six trials were included in the meta-analysis, including 2,381 patients (1,192 randomized to SES and 1,189 to BMS). Up to 12-month follow-up, TVR was significantly lower in patients treated with SES as compared to patients treated with BMS (4.53% vs. 12.53%, respectively; odds ratio [OR] 0.33; 95% confidence interval [CI] 0.24-0.46; P < 0.00001). There were no significant differences in the incidence of stent thrombosis (3.02% vs. 3.70%, OR = 0.81 [95% CI, 0.52-1.27], P = 0.81), cardiac death (2.77% vs. 3.28%, OR = 0.84 [95% CI, 0.52-1.35], P = 0.47), and recurrent MI (2.94% vs. 4.04%, OR = 0.71 [95% CI, 0.45-1.11], P = 0.13) between the two groups.

CONCLUSION

SES significantly reduces TVR rates as compared to BMS in STEMI patients up to 1 year follow-up. Further studies with larger population and longer follow-up time are needed to confirm our findings.