Severe mitral regurgitation complicating acute myocardial infarction: Clinical and angiographic differences between patients with and without papillary muscle rupture

Abstract

Aims To assess the differential clinical and angiographic characteristics of patients with severe mitral regurgitation related (n = 31) or unrelated (n=16) to papillary muscle rupture complicating acute myocardial infarction. Methods and resultsThe clinical and angiographic features of patients with myocardial infarction and severe mitral regurgitation were evaluated. Patients with papillary muscle rupture were older (67 vs 60 years, / ) <0005) and had a lower rate of diabetes (7% vs 38%, / > <0005) and of previous angina or infarction (24% vs 50%, P<005). Frequency of inferior infarction was high and comparable in both groups (papillary muscle rupture, 72% vs nonpapillary muscle rupture, 88%, ns) whereas in-hospital rate of angina/infarct extension prior to mitral regurgitation, also high, tended to be higher in patients without than in those with papillary muscle rupture (67% vs 39%, ns). Incidence of multivessel disease tended to be higher in patients without papillary muscle rupture (87% vs 56%, P<006) and they had a lower ejection fraction (46± 15 vs 61 ± 14%, P<003), whereas the culprit artery was mainly the right or the circumflex coronary artery in both groups (papillary muscle rupture, 100% vs non papillary muscle rupture, 93%, ns). Valve replacement was performed earlier in patients with papillary muscle rupture (1 (1; 14) vs 25 (5; 45) days, median, P<0002) but was associated with a similar mortality (papillary muscle rupture 11/24, 46% vs non-papillary muscle rupture, 7/15, 47%, ns). The main cause of death was cardiogenic shock in patients without papillary muscle rupture (5/7, 71%), and respiratory insufficiency-sepsis in those with papillary muscle rupture (7/11,64%). ConclusionsSevere mitral regurgitation in myocardial infarction with or without papillary muscle rupture is mostly related to inferior infarction and often follows reinfarction, particularly in non-papillary muscle rupture cases. The main contributors to surgical mortality appear to be respiratory insufficiency in patients with papillary muscle rupture and cardiogenic shock, facilitated by a lower ejection fraction, a higher frequency of diabetes and more extensive coronary disease, in patients without papillary muscle rupture.

Papillary Muscle Rupture Following Myocardial Infarction

“…Although an audible murmur in our patient led to studies that documented the presence of papillary muscle rupture, it may be quite difficult to hear a heart murmur in a patient with this serious mechanical complication of acute MI 14,15 . Despite the lack of extensive LV necrosis in most patients with papillary muscle rupture, 16 these patients typically present with cardiogenic shock 8,14,17 . Accordingly, the low LV systolic pressure, coupled with significant respiratory distress and accompanying tachypnea and pulmonary rales, may make it quite difficult to detect the murmur of MR in a patient with acute papillary muscle rupture.…”

“…The coronary vascular supply to the papillary muscles helps clarify which patients with acute MI are at risk for this complication. Typically, the anterolateral papillary muscle is supplied by the left circumflex coronary artery, whereas the posteromedial papillary muscle is supplied by either the left circumflex or the right coronary artery, 7–10 depending on whether the coronary circulation is left or right dominant. The left anterior descending coronary artery generally does not supply perfusion to the papillary muscles.…”

Double papillary muscle infarction related to right coronary artery occlusion: a case report

“…In a clinical study, Calvo et al [6] assessed the differential clinical and angiographic characteristics of patients with severe MR with regard to whether they were related (n=31) or unrelated (n=16) to ruptured papillary muscle complicated by acute MI. The study also showed that in the patients with papillary muscle rupture, the involvement of the RCA was higher than that of the Cx, whereas in those with non-papillary muscle rupture, both arteries seemed to be equally responsible for the MR.…”

Rupture of the Posteromedial Papillary Muscle Leading to Partial Flail of the Anterior Mitral Leaflet

“…1 It is postulated that the preserved contractility exerts increased stress on an already compromised papillary muscle, eventually leading to rupture. 2 This case highlights the importance of understanding mitral valve anatomy. The valve itself comprises an anterior and a posterior leaflet.…”