NEPHRON SPARING TECHNIQUES INDEPENDENTLY REDUCE THE RISK OF CARDIOVASCULAR EVENTS AFTER SURGERY IN PATIENTS WITH CLINICAL T1A-T1B RENAL MASS AND NORMAL PREOPERATIVE GLOMERULAR FILTRATION RATES: RESULTS FROM A LARGE MULTI-INSTITUTIONAL STUDY

INTRODUCTION AND OBJECTIVES: Some reports suggested that nephron sparing surgery (NSS) may protect against cardiovascular events (CE) when compared with radical nephrectomy (RN) in patients with small renal masses. However, the majority of those studies could not adjust their results for potential selection bias secondary to clinical baseline cardiovascular risk of the patients. In the current study, we aimed to test the effect of treatment type (NSS vs. RN) on prevalence of CE after accounting for clinical characteristics, comorbidities and individual cardiovascular risk. METHODS: A multi-institutional collaboration among four European Tertiary Care Centers allowed collecting 1331 patients with a clinical T1a-T1b N0 M0 renal mass and complete cardiovascular event follow-up data. Patients underwent RN (n¼462, 34.7%) or NSS (n¼869, 65.3%) and showed normal estimated glomerular filtration rates (eGFR) before surgery (defined as pre-operative eGFR60 ml/min/1.73 m2). CE was defined as the onset of coronary artery disease, hypertensive heart disease, heart failure, cardiac dysrhythmias or cerebrovascular disease. Cox regression analyses predicting CE were performed. To adjust for inherent baseline differences among patients, we relied on multivariable analyses adjusting for age, clinical tumor size, gender, presence of hypertension or diabetes, baseline Charlson comorbidity index (CCI) and smoker status. RESULTS: Mean patient age resulted 60.6 years (median 62). Overall, 14.7% and 11% of the patients had uncontrolled hypertension or diabetes, respectively. CCI resulted 0-1 in 70.8% of the patients. At a mean follow up period of 71 months, 197 patients (14.8%) developed a CE. When stratifying for treatment type, 10.5 vs. 22.9% patients developed CE (p<0.001). At multivariable analyses, patients who underwent PN showed significantly lower risk to harbour CE compared with their RN-treated counterparts (odds ratio [OR]: 0.50; 95% confidence interval, 0.26-0.96; p¼0.03). Presence of uncontrolled hypertension (HR: 3.97, p¼0.01) and smoker status (OR: 1.96, p¼0.05) resulted independent predictors of CE. CONCLUSIONS: The risk of cardiovascular event after renal surgery is not negligible. Patients treated with NSS have half of the risk to develop CE relative to RN counterparts. Also after accounting for clinical characteristics, comorbidities and cardiovascular risk at diagnosis, NSS independently decrease the risk of CE relative to RN.