Cardiorenal Syndrome Triggered by Slowly Progressive Drugs Toxicity-Induced Renal Failure along with Minimal Mitral Disease: A Case Report

Abstract

Background: We report the case of a 93-year-old patient with normal left ventricular function and severe mitral annulus calcification, with mild mitral steno-insufficiency.

Case presentation: She had developed creeping drugs-induced renal toxicity that is generally totally overlooked, due mainly to statins, a proton pump inhibitor, and aspirin. The Na and fluid retention, along with hypertension that ensued, although not severe, caused acute heart failure (sub-pulmonary edema) by worsening the mitral insufficiency. This occurred due to a less efficient calcific mitral annulus contraction during systole and an increasing mitral transvalvular gradient, as the transvalvular mitral gradient has an exponential relation to flow. After the suspension of the nephrotoxic drugs and starting intravenous furosemide, she rapidly improved. At 6 months follow-up, she is stable, in an NYHA 1-2 functional class, despite the only partial recovery of the renal function.

Conclusion: Progressive renal failure can functionally worsen even minimal mitral valvulopathy. Drug-induced nephrotoxicity can always be suspected in case of renal failure of unknown etiology. The suspension of the culprit drugs can improve renal function and dramatically improve the clinical symptoms even in a nonagenarian.

Keywords: Renal insufficiency; heart failure; kidney toxicity; mitral annulus calcification; nephrotoxicity; sub-pulmonary edema.