Medical therapy vs early revascularization in diabetics with chronic total occlusions: A meta-analysis and systematic review

BACKGROUND: Management of chronic total occlusions (CTO) in diabetics is challenging, with a recent trend towards early revascularization [ER: Percutaneous coronary intervention (PCI) and bypass grafting] instead of optimal medical therapy (OMT). We hypothesize that ER improves morbidity and mortality outcomes in diabetic patients with CTOs as compared to OMT. AIM: To determine the long term clinical outcomes and to compare morbidity and mortality between OMT and ER in diabetic patients with CTOs. METHODS: Potentially relevant published clinical trials were identified in Medline, Embase, chemical abstracts and Biosis (from start of the databases till date) and pooled hazard ratios (HR) computed using a random effects model, with significant P value < 0.05. Primary outcome of interest was all-cause death. Secondary outcomes included cardiac death, prompt revascularization (ER) or repeat myocardial infarction (MI). Due to scarcity of data, both Randomized control trials and observational studies were included. 4 eligible articles, containing 2248 patients were identified (1252 in OMT and 1196 in ER). Mean follow-up was 45-60 mo. RESULTS: OMT was associated with a higher all-cause mortality [HR: 1.70, 95% confidence interval (CI): 0.80-3.26, P = 0.11] and cardiac mortality (HR: 1.68, 95%CI: 0.96-2.96, P = 0.07). Results were close to significance. The risk of repeat MI was almost the same in both groups (HR: 0.97, 95%CI: 0.61-1.54, P = 0.90). Similarly, patients assigned to OMT had a higher risk of repeat revascularization (HR: 1.62, 95%CI: 1.36-1.94, P < 0.00001). Sub-group analysis of OMT vs PCI demonstrated higher all-cause (HR: 1.98, 95%CI: 1.36-2.87, P = 0.0003) and cardiac mortality (HR: 1.87, 95%CI: 0.96-3.62, P = 0.06) in the OMT group. The risk of repeat MI was low in the OMT group vs PCI (HR: 0.53, 95%CI: 0.31-0.91, P = 0.02). Data on repeat revascularization revealed no difference between the two (HR: 1.00, 95%CI: 0.52-1.93, P = 1.00). CONCLUSION: In diabetic patients with CTO, there was a trend for improved outcomes with ER regarding all-cause and cardiac death as compared to OMT. These findings were reinforced with statistical significance on subgroup analysis of OMT vs PCI.