Evaluating Long-Term Outcomes in STEMI Patients with New Left Bundle Branch Block: The Impact of Modifiable Risk Factors

Abstract

Background/Objectives: Coronary artery disease, a leading global cause of death, highlights the essential need for early detection and management of modifiable cardiovascular risk factors to prevent further coronary events. Methods: This study, conducted at a major tertiary academic PCI-capable hospital in Romania from 1 January 2011 to 31 December 2013, prospectively analyzed 387 myocardial infarction with ST-segment elevation (STEMI) patients to assess the long-term management of modifiable risk factors. This study particularly focused on patients with new-onset left bundle branch block (LBBB) and compared them with a matched control group without LBBB. Results: During median follow-up periods of 9.6 years for LBBB patients and 9.2 years for those without LBBB, it was found that smoking, obesity, and dyslipidemia were prevalent in 73.80%, 71.42%, and 71.42% of the LBBB group, respectively, at baseline. Significant reductions in smoking were observed in both groups, with the LBBB group’s smoking rates decreasing significantly to 61.90% (p = 0.034). Patients with LBBB more frequently achieved low-density lipoprotein cholesterol (LDLc) target levels during the follow-up period (from 71.42% to 59.52%; p = 0.026) compared to the control group (from 66.67% to 71.42%; p = 0.046). Prescription rates for dual antiplatelet therapy (DAPT), angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARBs), beta-blockers, and statins were initially high but then decreased by the follow-up. Statin use was reduced from 97.62% to 69.04% (p = 0.036) in the LBBB group and from 100% to 61.90% (p = 0.028) in the non-LBBB group. This study also highlighted moderate correlations between obesity (r = 0.627, p = 0.040) and subsequent coronary reperfusion in the LBBB group, while dyslipidemia and smoking showed very strong positive correlations across both groups (dyslipidemia: r = 0.903, p = 0.019 for LBBB; r = 0.503, p = 0.048 for non-LBBB; smoking: r = 0.888, p = 0.035 for LBBB; r = 0.517, p = 0.010 for non-LBBB). Conclusions: These findings underscore the crucial need for targeted management of modifiable risk factors, particularly focusing on dyslipidemia and smoking cessation, to improve subsequent coronary reperfusion outcomes post-STEMI, especially in patients with complicating factors like LBBB.