Clinical and echocardiographic presentation of postmyocardial infarction papillary muscle rupture

Severe mitral regurgitation (MR) can occur following myocardial infarction (MI) with either partial or complete papillary muscle rupture (pPMR or cPMR). Although the incidence of this complication has significantly decreased, it is still associated with significant mortality. We sought to evaluate the different echocardiographic and clinical presentations of pPMR and cPMR.

A review of all the urgent procedures for ischemic MR between January 2000 and June 2016 was performed to identify patients who underwent surgery for PMR. Surgical protocols and echocardiographic studies were used to identify patients with cPMR and pPMR. A total of 37 patients had cardiac surgery for PMR (18 cPMR, 19 pPMR). All patients with cPMR were in cardiogenic shock at the time of diagnosis, as opposed to only 53% of patients with pPMR (P = 0.0008). Between the time of diagnosis and surgery, 7 patients with pPMR developed cardiogenic shock. Transthoracic echocardiography (TTE) led to the diagnosis in 72% of cPMR and 32% of pPMR (P = 0.02). TEE had a yield of 100% for both cPMR and pPMR. Six pathologic varieties of post-MI PMR were recognized on echocardiography and during surgery. Early postoperative, 1 (72% vs 84%), 3 (67% vs 84%), and 5 years (67% vs 74%) survival rates were similar for cPMR and pPMR (P = 0.26).

Partial PMR is associated with a different clinical and echocardiographic presentation than cPMR. Still, most pPMR patients progress toward cardiogenic shock. Prompt diagnosis and referral for surgery are critical and could potentially decrease mortality.