Internal mammary artery graft failure: Clinical features, management, and long-term outcomes

Objective: Data on long-term outcomes after internal mammary artery (IMA) coronary graft failure are scarce. Our objective was to describe the clinical characteristics, management, and prognosis after angiographically confirmed IMA graft failure following coronary revascularization. Methods: A three-hospital retrospective registry, observational and descriptive, with prospective follow-up of all consecutive cases of IMA graft failure between 2004 and 2014 was conducted. After treatment, clinical and procedural features were compared between those with and without cardiovascular events. Results: Fifty-seven patients were included (89% male, mean age: 62 years, at surgery) in the registry. Most patients underwent an IMA angioplasty (percutaneous coronary intervention [PCI], 74%). In nine cases, the PCI failed at the graft level, and seven underwent a native vessel revascularization. Native vessel treatment was performed in 20% of the study subjects, all with stents. Finally, medical management was decided in three cases. Events after treatment for IMA graft failure were frequent (50.8%), during a median follow-up of 7.5 years. Acute presentation (hazard ratioMACE = 1.35; 95% confidence interval (CI): 1.12–3.00, p < 0.01), age of the patient (hazard ratioMACE = 1.85, 95% CI: 1.17–2.11, p < 0.01), presence of diabetes mellitus (hazard ratioMACE = 2.75, 95% CI: 1.13–6.69, p = 0.02), and the management modality used (IMA-simple angioplasty VS IMA-stenting: hazard ratioMACE = 5.5, 95% CI: 1.40–21.15, p = 0.01) displayed prognostic relevance on multivariate analysis. All-cause mortality occurred in 21.1% and presentation as infarction (hazard ratioDEATH = 1.05, 95% CI: 1.01–2.17, p = 0.01), age (hazard ratioDEATH = 9.08, 95% CI: 2.52–32.69, p < 0.01), and left ventricular ejection fraction (hazard ratioDEATH = 3.68, 95% CI: 1.65–8.18, p < 0.01) were independent predictors of the same. Conclusions: In this long-term registry, most patients presented with an acute condition (myocardial infarction, progressive angina) within 12 months after surgery. Acute presentation, age, diabetes mellitus, reduced left ventricular ejection fraction, IMA graft failure segment affected, and the management strategy were related with long-term prognosis. Keywords: Acute coronary syndrome, Coronary artery disease, Coronary bypass grafts, Percutaneous coronary intervention, Internal mammary arter