Clinical correlates of long-term mortality after percutaneous interventions of saphenous vein grafts

Abstract

Increasing number of patients undergo percutaneous intervention of saphenous vein grafts (SVGs). However, the clinical factors associated with long-term mortality after SVG interventions are currently less known. Accordingly, the goal of present study was to evaluate clinical correlates of long-term mortality and to develop a simple bedside tool for risk stratification in patients undergoing SVG interventions. We analyzed 1019 patients undergoing SVG interventions from the Duke Cardiovascular Disease Database (1986-2003). Cox proportional hazards model was used to identify baseline variables associated with long-term mortality, and the model variables were then used to construct a nomogram for survival probability at 4 years. At a median follow-up of 4 years, 24% of those undergoing SVG interventions died (interquartile range 2-7 years). Independent correlates of death at follow-up on multivariable analysis included presenting heart rate (hazard ratio [HR] 1.02, 95% CI 1.01-1.03), diabetes (HR 1.73, 95% CI 1.37-2.18), presenting heart failure (HR 1.62, 95% CI 1.27-2.06), age (per 10-year increase, HR 1.29, 95% CI 1.13-1.46), peripheral vascular disease (HR 1.59, 95% CI 1.23-2.04), renal insufficiency (HR 2.01, 95% CI 1.36-2.97), patent internal mammary graft (HR 0.67, 95% CI 0.53-0.86), body mass index < or = 25 kg/m2 (HR 0.91, 95% CI 0.85-0.97), carotid bruit (HR 1.44, 95% CI 1.12-1.85), S3 ventricular gallop (HR 1.83, 95% CI 1.11-3.03), and hypertension (HR 1.38, 95% CI 1.04-1.83) (c-index 0.83). Bootstrap validation confirmed excellent internal validity of the model (mean c-index 0.84, 95% CI 0.80-0.85). Long-term survival after SVG intervention is poor, with one fourth of patients dying at median follow-up of 4 years. The nomogram developed using the model variables provides a method for clinicians to advise patients undergoing SVG interventions regarding their long-term prognosis, thereby enhancing discharge and long-term follow-up planning and setting up of realistic expectations.