Effect of atrial fibrillation on outcome in patients with known or suspected coronary artery disease referred for exercise stress testing

Prevalence and Impact of Atrial Fibrillation on Prognosis in Takotsubo Cardiomyopathy Patients

The purpose of this review is to describe the impact of atrial fibrillation (AF) on the cardiovascular outcomes and prognosis in patients with Takotsubo Cardiomyopathy (TTC). The pathophysiological basis of TTC is set on the release of catecholamines, occurring post an emotional or stressful event. The cardiovascular system of patients with TTC is affected by the high concentrations of catecholamines, creating the ideal background for the development of AF: inflammation, myocardial stress, and excessive sympathetic activity. AF is considered to be the most frequent arrhythmia in TTC patients and is associated with higher rates of cardiovascular and all-cause mortality. AF is also linked with a worse prognosis concerning the hemodynamic status, cardiac fibrosis, lethal arrhythmias, thromboembolic events, and adverse heart failure associated outcomes. The early diagnosis of AF in these patients plays significant role in the prevention of adverse events, the reversibility of left ventricular function, and the restoration of sinus rhythm.

Predicting Mortality in Patients with Atrial Fibrillation and Obstructive Chronic Coronary Syndrome: The Bialystok Coronary Project

Over the next decades, the prevalence of atrial fibrillation (AF) is estimated to double. Our aim was to investigate the causes of the long-term mortality in relation to the diagnosis of atrial fibrillation (AF) and chronic coronary syndrome (CCS). The analysed population consisted of 7367 consecutive patients referred for elective coronary angiography enrolled in a large single-centre retrospective registry, out of whom 1484 had AF and 2881 were diagnosed with obstructive CCS. During follow-up (median = 2029 days), 1201 patients died. The highest all-cause death was seen in AF(+)/CCS(+) [194/527; 36.8%], followed by AF(+)/CCS(−) [210/957; 21.9%], AF(−)/CCS(+) [(459/2354; 19.5%)] subgroups. AF ([HR]_AC = 1.48, 95%CI, 1.09–2.01; HR_CV = 1.34, 95%CI, 1.07–1.68) and obstructive CCS (HR_AC = 1.90, 95%CI, 1.56–2.31; HR_CV = 2.27, 95%CI, 1.94–2.65) together with age, male gender, heart failure, obstructive pulmonary disease, diabetes were predictors of both all-cause and CV mortality. The main findings are as follow among patients referred for elective coronary angiography, both AF and obstructive CCS are strong and independent predictors of the long-term mortality. Mortality of AF without CCS was at least as high as non-AF patients with CCS. CV deaths were more frequent than non-CV deaths in AF patients with CCS compared to those with either AF or CCS alone.

Prognostic Value of Heart Rate Reserve in Patients with Permanent Atrial Fibrillation during Dipyridamole Stress Echocardiography

In patients in sinus rhythm, a blunted heart rate reserve (HRR) during dipyridamole stress echocardiography (SE) is a prognostically unfavorable sign of cardiac autonomic dysfunction. In this study we sought to assess the prognostic meaning of HRR in patients with permanent atrial fibrillation (AF). The study population was made by 301 patients (176 men, age 73 ± 8 years) with suspected (n = 200) or known (n = 101) coronary artery disease and permanent AF who underwent high-dose dipyridamole SE. HRR was calculated on an average of 5 consecutive beats as the peak/rest ratio of HR from 12-lead EKG. During a median follow-up time of 77 months (first quartile 44, third quartile 115 months), 111 (37%) patients died. Receiver operating characteristics analysis identified HRR ≤1.17 as the best predictor of mortality. At multivariable analysis, HRR ≤1.17 (HR 1.75, 95% CI 1.17 to 2.62; p = 0.006) independently predicted mortality together with age (HR 1.09, 95% CI 1.06 to 1.13; p <0.0001), rest wall motion score index (HR 1.69, 95% CI 1.01 to 2.83; p = 0.04), and systemic hypertension (HR 1.76, 95% CI 1.06 to 3.00; p = 0.04). The annual mortality was 5.1% in the overall population, 7.0% in the 140 (46%) patients with abnormal HRR and 3.5% in the 161 (54%) patients with normal HRR. The 8-year mortality was 48% in patients with abnormal HRR and 18% in those with normal HRR (p <0.0001). In conclusion, patients with suspected or known coronary artery disease with permanent AF with a blunted HRR have an increased mortality. HRR outweighs inducible ischemia for prediction of survival. The assessment of HRR should become an integral part of dipyridamole SE reading also in AF.

Heart rate reserve during dipyridamole stress test applied to potential heart donors in brain death

BACKGROUND

A blunted heart rate reserve (HRR) during dipyridamole stress echocardiography (DSE) is a prognostically unfavorable sign of cardiac autonomic dysfunction. Short-term adjustments of heart rate (HR) are thought to rise from changes in neural input to the heart. DSE is applied in potential heart donors to rule out underlying coronary artery disease and left ventricular dysfunction. The aim of this study is to assess HRR during DSE in brain death.

METHODS

We enrolled two groups: group 1 (N.=49, 22 men, 54.6±8.8 years) with patients in brain death enrolled in the nationwide marginal donor heart recruiting program; group 2 (N.=49, 18 men, 66.4±12.0 years) referred to DSE for suspected or known coronary artery disease. All underwent DSE (0.84 mg/kg in 6') by quality-controlled readers certified via web-based training (1487/CE Lazio-1). We assessed left ventricular contractile reserve (LVCR) as stress/rest ratio of force (systolic blood pressure/end-systolic volume). HRR was calculated as the peak/rest HR ratio from 12-lead EKG.

RESULTS

The two study groups were similar for prevalence of inducible ischemia (4/49 vs. 9/49, P=NS). Group 1 showed higher resting HR (group 1: 88.1±15.5 bpm vs. group 2: 66.5±11.5 bpm, P<0.01) and similar peak HR (group 1: 94.7±15.3 bpm vs. group 2: 89.5±19.3 bpm, P=0.144), with blunted HRR (group 1: 1.08±0.10 bpm vs. group 2: 1.36±0.31 bpm, P<0.01). HRR was unrelated to LVCR.

CONCLUSIONS

HRR is almost abolished and unrelated to LVCR in brain-dead patients during DSE. The modulation of neural input to the heart is essential to determine HRR, and plays no significant role in determining the inotropic response during DSE.

Atrial fibrillation and the risk for myocardial infarction, all-cause mortality and heart failure: A systematic review and meta-analysis

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.

Atrial fibrillation as a prognostic indicator of myocardial infarction and cardiovascular death: a systematic review and meta-analysis

This study aimed to investigate whether atrial fibrillation (AF) predicts myocardial infarction (MI) or cardiovascular (CV) death. AF is a well-established risk factor for thrombotic stroke and all-cause mortality. PubMed, EmBase, and Cochrane Central were searched for articles comparing the incidence rates of MI, CV death, or CV events between AF and non-AF patients. Relative risk ratio (RR) was used as effect estimate. Crude and adjusted RRs were calculated. Data were pooled using a random-effects model. The meta-analysis included 27 studies. In the unadjusted analysis, AF patients had a nonsignificant trend toward a higher risk of MI compared with non-AF patients; however, a significant association was found. The crude data analysis showed that AF was associated with increased risk of CV death (P < 0.05) and CV events (P < 0.05). These associations remained significant after pooling data from adjusted models (CV death: RR = 1.95, 95% CI 1.51–2.51, P < 0.05; CV events: RR = 2.10, 95% CI 1.50–2.95, P < 0.05). These results showed that AF is an independent risk factor for MI, CV death, and CV events.

Atrial fibrillation as risk factor for cardiovascular disease and death in women compared with men: systematic review and meta-analysis of cohort studies

OBJECTIVE

To determine whether atrial fibrillation is a stronger risk factor for cardiovascular disease and death in women compared with men.

DESIGN

Meta-analysis of cohort studies.

DATA SOURCES

Studies published between January 1966 and March 2015, identified through a systematic search of Medline and Embase and review of references.

ELIGIBILITY FOR SELECTING STUDIES

Cohort studies with a minimum of 50 participants with and 50 without atrial fibrillation that reported sex specific associations between atrial fibrillation and all cause mortality, cardiovascular mortality, stroke, cardiac events (cardiac death and non-fatal myocardial infarction), and heart failure.

DATA EXTRACTION

Two independent reviewers extracted study characteristics and maximally adjusted sex specific relative risks. Inverse variance weighted random effects meta-analysis was used to pool sex specific relative risks and their ratio.

RESULTS

30 studies with 4,371,714 participants were identified. Atrial fibrillation was associated with a higher risk of all cause mortality in women (ratio of relative risks for women compared with men 1.12, 95% confidence interval 1.07 to 1.17) and a significantly stronger risk of stroke (1.99, 1.46 to 2.71), cardiovascular mortality (1.93, 1.44 to 2.60), cardiac events (1.55, 1.15 to 2.08), and heart failure (1.16, 1.07 to 1.27). Results were broadly consistent in sensitivity analyses.

CONCLUSION

Atrial fibrillation is a stronger risk factor for cardiovascular disease and death in women compared with men, though further research would be needed to determine any causality.