Early observations of the effect of extracorporeal shockwave lithotripsy on blood pressure: a prospective randomized control clinical trial

OBJECTIVE: To determine, in a randomized controlled clinical trial, the effect of extracorporeal shock wave lithotripsy (ESWL) on blood pressure. PATIENTS AND METHODS: The trial included 228 patients with small (< 15 mm) asymptomatic calyceal stones who were randomised to undergo ESWL (113 patients) or to an untreated (observed) control group (115 patients). Blood pressure was recorded at randomization using a standardized protocol. Patients undergoing ESWL received a mean (SD) of 5281 (3462) shocks over a mean of 1.75 sessions on one of two lithotripters. Patients were then followed annually, assessing blood pressure and changes in medication. Data were analysed on an intention-to-treat basis. RESULTS: At randomization, 43% of patients in the control group and 53% in the ESWL group were hypertensive. Of the 228 randomized, 200 patients completed at least one annual follow-up, of whom 192 (93 in the control and 99 in the ESWL group) had their blood pressure recorded. The mean follow-up was 2.2 years; 35 (37%) patients in the control and 46 (46%) in the ESWL group were hypertensive (P = 0.19). Seven (7%) patients in the control group and 11 (11%) in the ESWL group were newly diagnosed to be hypertensive (P = 0.35). CONCLUSIONS: In this randomized controlled clinical trial there was no evidence that ESWL causes changes in blood pressure.