Atrial Fibrillation and Risk of ST-Segment–Elevation Versus Non–ST-Segment–Elevation Myocardial Infarction

Abstract

Background It has recently been reported that atrial fibrillation [AF] is associated with an increased risk of myocardial infarction [MI]. However, the mechanism underlying this association is currently unknown. Further study of the relationship of AF with type of MI [ST elevation MI (STEMI) vs. non-ST elevation MI [NSTEMI] might shed light on the potential mechanisms. Methods and Results We examined the association between AF and incident MI in 14,462 participants [mean age 54 years, 56% women, 26% African Americans] from the Atherosclerosis Risk in Communities study who were free of coronary heart disease at baseline [1987–1989] with follow-up through December 31, 2010. AF cases were identified from study visits electrocardiogram and by review of hospital discharge records. Incident MI and its types were ascertained by an independent adjudication committee. Over a median follow up of 21.6 years, 1374 MI events occurred [829 NSTEMI, 249 STEMI, 296 unclassifiable]. In a multivariable adjusted model, AF [n=1545] as a time-varying variable was associated with a 63% increased risk of MI [HR (95% CI):1.63(1.32–2.02)]. However, AF was associated with NSTEMI [HR (95% CI): 1.80(1.39–2.31)] but not STEMI [HR (95% CI): 0.49(0.18–1.34)]; p-value for hazard ratios comparison=0.004. Combining the unclassifiable MI group with either STEMI or NSTEMI did not change this conclusion. The association between AF and MI, total and NSTEMI, was stronger in women than in men [interaction p-value<0.01 for both]. Conclusions AF is associated with an increased risk of incident MI, especially in women. However, this association is limited to NSTEMI.

Atrial fibrillation and risks of cardiovascular disease, renal disease, and death: systematic review and meta-analysis

“…In the case of myocardial infarction, atrial fibrillation could contribute to demand infarction and the subsequent development of type 2 myocardial infarction. 7 It is also possible that the association between atrial fibrillation and non-stroke cardiovascular disease is not causal. Considering our observation that atrial fibrillation is also associated with an increased risk of heart failure, sudden cardiac death, and chronic kidney disease (in addition to ischaemic heart disease), it seems likely that atrial fibrillation could be acting as a marker for shared underlying risk factors for cardiovascular disease.…”

Does Myocardial Infarction Beget Atrial Fibrillation and Atrial Fibrillation Beget Myocardial Infarction?

“…In the current issue of Circulation, Soliman et al 8 describe the association of AF with myocardial infarction. Similar findings in 2 other cohorts by the same lead author have been published in the last few months.…”

“…18,19 The opposite, that AF may beget myocardial infarction, also seems true, as was convincingly demonstrated by the studies by Soliman and colleagues. [8][9][10] AF may lead to myocardial infarction through increased heart rate and thus increased oxygen demand, sympathetic activation, endothelial dysfunction, and proinflammatory and prothrombotic effects (Figure). 14 The finding that NSTEMI, but not STEMI, was associated with AF supports the notion that recurrent ischemia is more frequently associated with NSTEMI compared with STEMI.…”

Myocardial Perfusion Is Impaired and Relates to Cardiac Dysfunction in Patients With Atrial Fibrillation Both Before and After Successful Catheter Ablation

“…Large‐scale prospective data demonstrate a clear association between AF and incident myocardial infarction in individuals without coronary heart disease, independent of conventional risk factors 2. The association is exclusive to non–ST‐elevation myocardial infarction,3 implicating an underlying pathophysiology of oxygen supply‐demand imbalance rather than complete thrombotic coronary occlusion. Clinicians are also familiar with patients with AF presenting with chest pain and evidence of cardiac ischemia or necrosis, such as “rate‐related” ST depression or troponin release, in the absence of significant epicardial coronary artery disease 4, 5.…”