External Outflow Graft Stenosis in Patients With Heartmate 3 Left Ventricular Assist Devices.

External outflow graft stenosis (eOGS) is an emerging long-term complication in left ventricular assist device (LVAD) patients. This study investigates its incidence, clinical presentation, management, and outcomes. We reviewed all HeartMate 3 LVAD patients implanted at our center (2016-2024). Since 2022, a computed tomography angiography (CTA) screening protocol has been implemented to facilitate early detection of eOGS, which is defined as ≥25% obstruction and classified as mild (25-49%), moderate (50-74%), or severe (≥75%). Among 125 patients (median follow-up: 33.7 months), 23 (18.4%) developed eOGS: 11 mild, 10 moderate, and two severe. Incidence rose from 2.1% at 1 year to 17.8% at 5 years. Of 12 patients with ≥50% stenosis, five were identified through screening, while others presented symptomatically, including two in cardiogenic shock during sepsis. Most symptomatic patients presented before routine screening was implemented. Seven patients underwent percutaneous stenting without complications; two required surgery, with one postoperative death. Of the three untreated patients, one experienced sudden cardiac arrest from total eOGS. Mortality was higher in patients with eOGS ≥50% (hazard ratio [HR]:1.65; 95% confidence interval [CI]: 1.28-1.89). External outflow graft stenosis prevalence increases over time and negatively impacts survival. Routine CTA screening enables early diagnosis and timely treatment. Percutaneous management appears to be a safe and effective treatment option.