No Clinical Evidence for Protective Effects of Calcium-Channel Blockers against Acute Renal Failure

To the Editor: Calcium-channel blockers, specifically verapamil, have been shown in animal studies to protect the kidneys against long-term damage after an ischemic insult consisting of an intra-arterial infusion of norepinephrine. 1 Similar studies have demonstrated protective effects in cases of cold ischemia as well as ischemia due to acute vascular insufficiency. 2 , 3 We conducted a retrospective study looking for the same protective effect in human beings. We analyzed 64 patients who had undergone either coronary artery bypass or valve replacement surgery within the preceding six months; 15 patients were excluded because records of perioperative death were inadequate. The patients were divided . . .