Spontaneous Left Main Dissection: Clinical Characteristics, management and Outcomes

Courtesy of Dr. Juan Manuel Pérez.

Spontaneous left main dissection in an uncommon, and potentially life-threatening, cause of acute MI. The aim of this study, was to look into the clinical characteristics, treatment and outcomes of these patients. 

This was a systematic review of cases published between 1990 and 2023. After analyzing 1,106 articles from MEDLINE and Embase databases, 132 patients were selected, excluding those with iatrogenic dissection. Patients were classified according to management: conservative or invasive revascularization (PCI or CABG). 

132 patients with spontaneous left main dissection were analyzed (mean age: 40 ± 11 years; 80% women), associated to pregnancy in 36% of cases and presented with acute coronary syndrome (ACS) in 95% (64% ST elevation MI (STEMI), 27% non ST elevation MI (NSTEMI) and, y 6% unstable angina). 22% presented with cardiogenic shock, 8% with ventricular arrhythmia, and mean left ventricular ejection fraction was 40% ± 13%. Coronary flow was limited (TIMI <3) in 74% and multivessel disease in 78%, predominantly in the anterior descending (68%).

40% were managed conservatively and 60% invasively (61% CABG, 39% PCI), with 100% success rate for CABG and 81% for PCI. Women and younger patients were more often managed conservatively (89% vs. 73%; p=0.033 and 38 vs. 42 years; p=0.022, respectively). Patients with cardiogenic shock or TIMI <3 tended to receive invasive treatment. 

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With mean 120 day followup (interquartile range: 30–365 days), mortality rate resulted 9%, left ventricular assistance device (LVAD) or heart transplant 4%, recurrent MI 13% and emergency revascularization 22%. 32% of patient presented the composite end point of death, LVAD or transplant, recurrent MI or emergency revascularization, with lower incidence among invasive management patients (17% vs. 51% for conservative management; adjusted HR: 0.37; CI95%: 0.20–0.69; p<0.001).

Among invasive management patients, CABG showed better results vs PCI in hemodynamically stable patients (HR: 0.18; CI95%: 0.04–0.98; p=0.04), with no significant differences in unstable patients. The use of intracoronary images was limited (24%). As regards drug therapy, 63% received beta-blockers, 55% dual antiaggregation and 31% statins.

Conclusions

To sum up, spontaneous left main dissection affects mainly young women and is associated with high morbimortality in its acute phase. Data suggest early revascularization with PCI or CABG is associated to better outcomes vs conservative management, especially in terms of lower MI recurrence and need for emergency revascularization. In hemodynamically stable patients, CABG might be preferred. These findings require confirmation from prospective registries and future clinical trials. 

Original Title: Left Main Spontaneous Coronary Artery Dissection: Clinical Features, Management, and Outcomes.

Reference: Michele Morosato et al. JACC: Cardiovascular Interventions, Volumen -, 2025.