Quantification of Myocardial Mass Using Coronary Computed Tomography Angiography in Bifurcation PCI and Association With Outcomes

OBJECTIVES: To determine if quantification of the myocardial mass supplied by a side branch (SB) could be predictive of bifurcation percutaneous coronary intervention (PCI) outcomes. METHODS: The authors examined the characteristics and outcomes of 73 patients (81 lesions) who underwent bifurcation PCI and had coronary computed tomography angiography (CCTA) angiography based computed flow-based calculation of myocardial mass at risk within 6 months prior. RESULTS: The lesions analyzed were complex with high V-RESOLVE scores (12.0, 95%, interquartile range [IQR]: 9.0, 13.5). Provisional stenting was used in 67.9%, 2-stent techniques in 32.1%, and conversion from provisional to 2-stent stenting was performed in 11.1% of the lesions. The main vessel (MV) supplied 30.0% (IQR: 24.0%, 36.0%) and the SB supplied 10.0% (IQR: 7.0%, 13.0%) of the myocardium. Technical success was 94.9%. Major adverse cardiovascular events (MACE) occurred in 5.5% of the patients and SB occlusion (SBO) in 12.3% of the lesions. The ratio of SB to MV myocardial mass supply (SB/MV) was not associated with technical success (odds ratio [OR], 11.00; 95% confidence interval [CI], 0.01, 18.79; P = .500) or MACE (OR, 0.02; 95% CI, 0.00, 18.20; P = .300), but was associated with SBO (OR, 6.02*10-6; 95% CI, 2.42*10-10, 0.15; P = .020). SB/MV was normally distributed (W = 0.99, P = .467) with a mean of 0.35 (95% CI, 0.31, 0.38). In lesions where SBO occurred, V-RESOLVE scores were higher (16.0 vs 12.0, P = .017) and the SB/MV ratio was lower (0.22 vs 0.35, P = .007). CONCLUSIONS: Myocardial mass derived from CT analysis can help assess the risk of SBO after bifurcation PCI.