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

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.

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.

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 ratio_MACE = 1.35; 95% confidence interval (CI): 1.12-3.00, p < 0.01), age of the patient (hazard ratio_MACE = 1.85, 95% CI: 1.17-2.11, p < 0.01), presence of diabetes mellitus (hazard ratio_MACE = 2.75, 95% CI: 1.13-6.69, p = 0.02), and the management modality used (IMA-simple angioplasty VS IMA-stenting: hazard ratio_MACE = 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 ratio_DEATH = 1.05, 95% CI: 1.01-2.17, p = 0.01), age (hazard ratio_DEATH = 9.08, 95% CI: 2.52-32.69, p < 0.01), and left ventricular ejection fraction (hazard ratio_DEATH = 3.68, 95% CI: 1.65-8.18, p < 0.01) were independent predictors of the same.

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.