Sudden death and its predictors in myocardial infarction survivors in an Indian population

Association between admission heart rate and major adverse cardiovascular events in acute myocardial infarction participants with different left ventricular ejection fraction

BACKGROUND

This study intended to investigate the independent effect of admission heart rate (HR) on the risk of major adverse cardiovascular events (MACEs) in acute myocardial infarction (AMI) patients with different left ventricular ejection fraction (LVEF) levels.

METHODS

The study was a secondary analysis of the Acute Coronary Syndrome Quality Improvement in Kerela Trial. The relationship between admission HR and 30-day adverse outcomes in AMI patients with different LVEF levels was detected using a Logistic regression model. Interaction tests were used to compare the effects of different subgroups on HR and MACEs.

RESULTS

Our study enrolled 18,819 patients. In both partially and fully adjusted models (Model1 and Model2), the risk of MACEs was highest in patients with HR ≥ 120 (OR: 1.62, 95%CI: (1.16, 2.26), P = 0.004, Model1; OR: 1.46, 95%CI: (1.00, 2.12), P = 0.047, Model2). There was a significant interaction between LVEF and HR (P for interaction = 0.003). Meanwhile, the trend test for this association showed that HR was positively and significantly associated with the MACEs in LVEF≥40% group (OR (95%CI): 1.27 (1.12, 1.45), P < 0.001). However, in LVEF<40% group, the trend test was not statistically significant (OR (95%CI): 1.09 (0.93, 1.29), P = 0.269).

CONCLUSION

This study found that elevated admission HR was associated with a significantly higher risk for MACEs in patients admitted with AMI. Elevated admission HR was significantly associated with the risk of MACEs in AMI patients without low LVEF but not those with low LVEF (<40%). LVEF levels should be considered when evaluating the association between admission HR and the prognosis of AMI patients in the future.

T-Wave Analysis on the 24 h Holter ECG Monitoring as a Predictive Assessment of Major Adverse Cardiovascular Events in Patients with Myocardial Infarction: A Literature Review and Future Perspectives

Myocardial ischemia is a pathophysiological state characterized by inadequate perfusion of the myocardium, resulting in an imbalance between myocardial oxygen demand and supply. It is most commonly caused by coronary artery disease, in which atherosclerotic plaques lead to luminal narrowing and reduced blood flow to the heart. Myocardial ischemia can manifest as angina pectoris or silent myocardial ischemia and can progress to myocardial infarction or heart failure if left untreated. Diagnosis of myocardial ischemia typically involves a combination of clinical evaluation, electrocardiography and imaging studies. Electrocardiographic parameters, as assessed by 24 h Holter ECG monitoring, can predict the occurrence of major adverse cardiovascular events in patients with myocardial ischemia, independent of other risk factors. The T-waves in patients with myocardial ischemia have prognostic value for predicting major adverse cardiovascular events, and their electrophysiological heterogeneity can be visualized using various techniques. Combining the electrocardiographic findings with the assessment of myocardial substrate may offer a better picture of the factors that can contribute to cardiovascular death.

Contributions of the heart rate turbulence method to risk stratification in patients after myocardial infarction: a review

Coronary artery disease remains an important cause of morbidity and mortality worldwide. The impact of ventricular arrhythmias and impaired cardiac vagal activity on coronary events is one of the most relevant prognostic factors, despite little research being conducted in clinical practice. A simple and cost-effective way to analyze cardiac autonomic regulation is through the heart rate turbulence (HRT) method. Studies have shown that altered HRT, which indicates reduction in the vagal cardiac activity, can identify patients who are at a higher risk of sudden death. Thus, aspects related to the definition, pathophysiological mechanism, conditions that alter the HRT behavior, and the main studies that analyzed the prognostic importance of HRT in patients with ischemic disease were discussed in this review. HRT analysis was proven to be a simple and cost-effective way to assess cardiac autonomic dysfunction by providing complementary information to classic parameters, such as the assessment of ventricular function.