Post percutaneous coronary interventional outcomes on proximal vs non-proximal lesions of the left and right coronary arteries: A systematic review and meta-analysis

BACKGROUND: The prognosis of patients with coronary artery disease is mainly related to the extent of myocardium at risk. Proximal coronary arteries, especially the proximal left anterior descending coronary artery (LAD), supply a large part of the myocardium. In this analysis, we aimed to systematically compare the post percutaneous coronary interventional (PCI) outcomes observed with proximal vs non-proximal lesions of the left and right coronary arteries. METHODS: MEDLARS Online, Excerpta Medica database, www.ClinicalTrials.gov, and the Cochrane databases were searched for relevant studies comparing the post PCI outcomes reported on proximal vs non-proximal lesions of the coronary arteries. RevMan software version 5.3 was used to analyze the data to generate respective results. Odds ratios (OR) and 95% confidence intervals (CI) were derived to represent the results appropriately. RESULTS: Six studies with a total number of 11,109 participants who were enrolled between 1990 and 2015 were included in this analysis. The current results showed major adverse cardiac events (MACEs) (OR: 1.28, 95% CI: 1.14–1.45; P = .0001) and mortality (OR: 1.70, 95% CI: 1.43–2.03; P = .00001) to be significantly higher with proximal compared to non-proximal coronary lesions irrespective of the follow-up time periods. However, re-infarction (OR: 1.05, 95% CI: 0.80–1.38; P = .71), repeated revascularization (OR: 1.08, 95% CI: 0.92–1.27; P = .35) and stent thrombosis (OR: 0.59, 95% CI: 0.27–1.31; P = .20) were not significantly different. When patients specifically with LAD lesions were compared with associated non-proximal lesions, mortality was still significantly higher with proximal lesions (OR: 2.26, 95% CI: 1.52–3.36; P = .0001). However, when patients with right proximal coronary artery lesions were compared with the corresponding non-proximal lesions, no significant difference was observed in mortality. CONCLUSION: In-hospital and long-term MACEs and mortality were significantly higher in patients with proximal compared to non-proximal coronary lesions following PCI. In addition, mortality was significantly higher in patients with proximal LAD lesions whereas no significant difference was observed in patients with right proximal coronary artery lesions. Larger trials should further confirm these hypotheses.