Cardiology Resident Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval Québec, Quebec, Canada
Background: Ventricular septal defect (VSD) is a rare complication of myocardial infarction. A prior study from our institution based on the experience before 2014 observed a 30-day mortality of 65% for VSD repairs. At that time, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and heart transplantation were not commonly used. In the last decade, treatment was refined, including timing of surgery, early VA-ECMO and heart transplant. This study comprehensively examines our institution’s management of VSD and patients’ outcomes.
METHODS AND RESULTS: This retrospective study includes 31 patients admitted between July 2014 to July 2023 with ischemic VSD at IUCPQ-UL (mean 66±11 years-old, 61% of men). Nineteen patients had antero-apical VSD (61%), and 12 had posterior VSD (39%). The mean VSD size was 15±8 mm, but posterior VSD were larger than antero-apical VSD (p=0.0011). The mean left ventricular ejection fraction (LVEF) was 41±8%, and 7 patients (23%) had a severe right ventricular dysfunction. Twenty patients (65%) developed cardiogenic shock before surgery, of which 9 required VA-ECMO support. These 9 patients were more hemodynamically unstable: higher lactate (p=0.002) and creatinine (p=0.002), worse right ventricular dysfunction (p < 0.001), and presented more often a posterior VSD (p=0.041). Overall, 30-day all-cause mortality was 35.5% (n=11). Two patients died before surgery, and of 29 patients who had surgery, 23 had VSD repair, and 6 underwent heart transplantation. Of the 6 transplants, 4 are still alive at 1-year. No difference was observed between patients who had a heart transplantation compared to patients who had a surgical VSD repair regarding LVEF (p=0.97) and VSD size (p=0.12), but patients who needed transplantation presented with worse right ventricular dysfunction (p < 0.001) and had more posterior VSD (p=0.012). Survivors had a longer delay between myocardial infarction and surgery vs. non-survivors (10 [5.5-13.5] vs. 4 days [3-4], p=0.009), and Kaplan-Meier survival estimates demonstrated that survival time was longer in patients waiting at least 6 days between myocardial infarction and surgery (p=0.015; hazard ratio 0.14; Figure 1). No death occurred between discharge and 1-year.
Conclusion: Compared to VSD management before 2014, we observed a marked improvement in 30-day mortality (35.5% vs. 65%) with thoughtful use of VA-ECMO, referral for heart transplantation when VSD repair is too risky, and well-timed surgery. Although mortality associated with VSD remains high, waiting at least 6 days between myocardial infarction and surgery provides a better prognosis, and VA-ECMO is a valuable option for bridging to well-timed surgery (Figure 2).
