Useful aid or futile hassle - continuous rhythm monitoring following acute myocardial infarction

Abstract Background Patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) face an increased risk of cardiac events, including arrhythmias. Current guidelines therefore recommend ECG monitoring for at least 24 hours after AMI in patients with ST segment elevation myocardial infarction (STEMI) and high-risk non-ST segment elevation myocardial infarction (NSTEMI). However, in the last decades medical treatment of AMI has been substantially improved, limiting the risk of arrhythmias post-PCI. Furthermore, continuous ECG monitoring puts additional strain on healthcare personnel during an international healthcare crisis. Purpose To evaluate the contemporary burden of ventricular arrhythmias (VA) in AMI patients post-PCI. Methods This is a retrospective analysis of consecutive patients undergoing PCI for AMI between 2016 and 2020 at a secondary care centre. We defined the primary endpoint as any VA requiring intervention (electric cardioversion or pharmacologic treatment) after PCI. Baseline characteristics and outcome were compared in patients with NSTEMI vs. STEMI. Results A total of 931 patients were included in the analysis, with a mean age of 65 years and 28.6% were female. Patients with NSTEMI (47.3%) were older (median 66 vs. 63 years) and had significantly more comorbidities: hypertension (67.5% vs. 52.1 %), diabetes mellitus (25.4% vs. 15.8%), chronic obstructive pulmonary disease (11.5% vs. 6.7%), and peripheral arterial disease (11.4% vs. 5.3%, p0.05 for all). VAs requiring intervention occurred in 3.6% vs. 7.1% (p = 0.017) before PCI and in 0% vs. 2.2% (p 0.001) during PCI in NSTEMI vs. STEMI patients. After PCI the primary endpoint occurred in no NSTEMI patient and in 1.6% of patients with STEMI (p = 0.004). Discussion In a cohort of contemporary AMI patients, ventricular arrhythmias occurred rarely and significantly less often in NSTEMI patients compared to STEMI patients. Due to the low risk of VAs in patients with NSTEMI after PCI, the need for post-procedural rhythm monitoring in NSTEMI patients may be questioned. The identification of predictors for VA after AMI should be subject for future trials.