Background: In contemporary atrial fibrillation trials most deaths are cardiac related, whereas stroke and bleeding represent only a small subset of deaths. We aimed to evaluate the long-term risk of cardiac events and all-cause mortality in individuals with atrial fibrillation compared to no atrial fibrillation. Design: A systematic review and meta-analysis of studies published between 1 January 2006 and 21 October 2016. Methods: Four databases were searched. Studies had follow-up of at least 500 stable patients for either cardiac endpoints or all-cause mortality for 12 months or longer. Publication bias was evaluated and random effects models were used to synthesise the results. Heterogeneity between studies was examined by subgroup and meta-regression analyses. Results: A total of 15 cohort studies was included. Analyses indicated that atrial fibrillation was associated with an increased risk of myocardial infarction (relative risk (RR) 1.54, 95% confidence interval (CI) 1.26–1.85), all-cause mortality (RR 1.95, 95% CI 1.50–2.54) and heart failure (RR 4.62, 95% CI 3.13–6.83). Coronary heart disease at baseline was associated with a reduced risk of myocardial infarction and explained 57% of the heterogeneity. A prospective cohort design accounted for 25% of all-cause mortality heterogeneity. Due to there being fewer than 10 studies, sources of heterogeneity were inconclusive for heart failure. Conclusions: Atrial fibrillation seems to be associated with an increased risk of subsequent myocardial infarction in patients without coronary heart disease and an increased risk of, all-cause mortality and heart failure in patients with and without coronary heart disease.

Guidelines concerning β-blocker treatment following acute myocardial infarction (AMI) are based on studies undertaken before the implementation of reperfusion and secondary prevention therapies. We aimed to estimate the effect of oral β-blockers on mortality in contemporary post-AMI patients with low prevalence of heart failure and/or reduced left ventricular ejection fraction. A random effects model was used to synthetize results of 16 observational studies published between 1 January 2000 and 30 October 2017. Publication bias was evaluated, and heterogeneity between studies examined by subgroup and random effects meta-regression analyses considering patient-related and study-level variables. The pooled estimate showed that β-blocker treatment [among 164 408 (86.8%) patients, with median follow-up time of 2.7 years] was associated with a 26% reduction in all-cause mortality [rate ratio (RR) 0.74, 95% confidence interval (CI) 0.64–0.85] with moderate heterogeneity (I² = 67.4%). The patient-level variable mean age of the cohort explained 31.5% of between study heterogeneity. There was presence of publication bias, or small study effect, and when controlling for bias by the trim and fill simulation method, the effect disappeared (adjusted RR 0.90, 95% CI 0.77–1.04). Also, small study effect was demonstrated by a cumulative meta-analysis starting with the largest study showing no effect, with increasing effect as the smaller studies were accumulated. Evidence from this study suggests that there is no association between β-blockers and all-cause mortality. A possible beneficial effect in AMI survivors needs to be tested by large randomized clinical trials.

The evidence supporting beta-blocker therapy after myocardial infarction was established before the introduction of modern coronary reperfusion therapy and secondary prevention strategies. In an open-label, randomized trial with blinded end-point evaluation, conducted in Denmark and Norway, we assigned patients who had had a myocardial infarction and who had a left ventricular ejection fraction of at least 40%, in a 1:1 ratio, to receive long-term beta-blocker therapy within 14 days after the event or no beta-blocker therapy. The primary end point was a composite of death from any cause or major adverse cardiovascular events (new myocardial infarction, unplanned coronary revascularization, ischemic stroke, heart failure, or malignant ventricular arrhythmias). A total of 5574 patients underwent randomization and were included in the main analyses - 2783 in the beta-blocker group and 2791 in the no-beta-blocker group. After a median follow-up of 3.5 years (interquartile range, 2.2 to 4.6), a primary end-point event had occurred in 394 patients (14.2%) in the beta-blocker group and in 454 patients (16.3%) in the no-beta-blocker group (hazard ratio, 0.85; 95% confidence interval [CI], 0.75 to 0.98; P = 0.03). Death from any cause occurred in 4.2% of the patients in the beta-blocker group and in 4.4% of those in the no-beta-blocker group; myocardial infarction occurred in 5.0% and 6.7%, respectively (hazard ratio, 0.73; 95% CI, 0.59 to 0.92), unplanned coronary revascularization in 3.9% and 3.9%, ischemic stroke in 1.6% and 1.3%, heart failure in 1.5% and 1.9%, and malignant ventricular arrhythmias in 0.5% and 0.6%. No apparent differences in safety outcomes were observed between the groups. Among patients with a myocardial infarction and a left ventricular ejection fraction of at least 40%, beta-blocker therapy led to a lower risk of death or major adverse cardiovascular events than no beta-blocker therapy. (Funded by the Health South-East research program in Norway and others; BETAMI-DANBLOCK ClinicalTrials.gov numbers, NCT03646357 and NCT03778554.).

Patients evaluated for acute and chronic chest pain comprise a large, heterogeneous group that often provides diagnostic challenges. Although speckle tracking echocardiography (STE) has proved to have diagnostic value in acute coronary syndrome it is not commonly incorporated in everyday practice. The purpose of the present systematic review was to assess the diagnostic accuracy of left ventricular (LV) longitudinal function by STE to predict significant coronary artery stenosis (CAD+) or not (CAD-) verified by coronary angiography in patients with chest pain suspected to be of cardiac ischemic origin. 4 electronic databases; Embase, Medline, Cochrane and PubMed ahead-of print were searched for per 19.05.14. Only full-sized articles including > 40 patients were selected. A total of 166 citations were identified, 16 full-size articles were assessed of which 6 were found eligible for this review. Of 781 patients included 397 (60 %) had CAD+. The overall weighted mean global longitudinal strain (GLS) was −17.2 % (SD = 2.6) among CAD+ vs. -19.2 % (SD = 2.8) in CAD- patients. Mean area under curve in 4 studies for predicting CAD+ ranged from 0.68 to 0.80. The study cut-off levels for prediction of CAD+ in the ROC analysis varied between −17.4 % and −19.7 % with sensitivity from 51 % to 81 % and specificity between 58 % and 81 %. In 1 study GLS obtained during dobutamine stress echocardiography (DSE) had the best accuracy. Regional strain measurements were not uniform, but may have potential in detecting CAD. GLS measurements at rest only have modest diagnostic accuracy in predicting CAD+ among patients presenting with acute or chronic chest pain. The results from regional strain, layer specific strain and DSE need to be verified in larger studies.

Current guidelines on the use of β-blockers in post-acute myocardial infarction (MI) patients without reduced left ventricular ejection fraction (LVEF) are based on studies before the implementation of modern reperfusion and secondary prevention therapies. It remains unknown whether β-blockers will reduce mortality and recurrent MI in contemporary revascularized post-MI patients without reduced LVEF. BETAMI is a prospective, randomized, open, blinded end point multicenter study in 10,000 MI patients designed to test the superiority of oral β-blocker therapy compared to no β-blocker therapy. Patients with LVEF ≥40% following treatment with percutaneous coronary intervention or thrombolysis and/or no clinical signs of heart failure are eligible to participate. The primary end point is a composite of all-cause mortality or recurrent MI obtained from national registries over a mean follow-up period of 3 years. Safety end points include rates of nonfatal MI, all-cause mortality, ventricular arrhythmias, and hospitalizations for heart failure obtained from hospital medical records 30 days after randomization, and from national registries after 6 and 18 months. Key secondary end points include recurrent MI, heart failure, cardiovascular and all-cause mortality, and clinical outcomes linked to β-blocker therapy including drug adherence, adverse effects, cardiovascular risk factors, psychosocial factors, and health economy. Statistical analyses will be conducted according to the intention-to-treat principle. A prespecified per-protocol analysis (patients truly on β-blockers or not) will also be conducted. The results from the BETAMI trial may have the potential of changing current clinical practice for treatment with β-blockers following MI in patients without reduced LVEF. EudraCT number 2018-000590-75.