Functional mitral regurgitation (MR) is one of the most common concomitant valvular lesions in the setting of aortic stenosis (AS), in particular with patients with an enlarged left ventricular chamber. The combination of AS and MR raises important challenges with regard to the therapeutic management of both AS and MR. Readmission for heart failure (HF) occurs in as many as 25% of patients within the first year following transcatheter aortic valve replacement (TAVR). A recent analysis of data from the PARTNER-1 trial, which included 2467 patients successfully treated and followed for 5 years, reported an incidence of first readmission for HF of 15% at 1 year and 23% at 5 years. This study identified: (1) lower transaortic pressure gradient at baseline; and (2) higher residual transaortic pressure gradient, MR grade, and paravalvular aortic regurgitation grade at discharge as being among the most significant risk factors associated with the occurrence of acute decompensated HF after TAVR. This commentary will discuss the pathophysiology and hemodynamic underpinnings of these risk factors.