Abstract 4118070: High Output Heart Failure After Leadless Pacemaker Placement In a Heart Transplant Recipient

Introduction: The advent of leadless pacemaker (LP) technology has revolutionized cardiac rhythm management by minimizing risks associated with traditional transvenous pacemakers. LP use is expected to increase as dual-chamber LP systems emerge into clinical practice. The LP requires a large-bore venous sheath (27-Fr) through a femoral vein. One risk of large bore femoral cannulation is creation of an occult arteriovenous fistula (AVF), which can cause high output heart failure (HOHF) over time. In the LEADLESS II trial, the event rate for AVF was 0.2%. HOHF as a complication of LP implant has not been previously reported. We describe the first case of HOHF in a heart transplant (HT) recipient after LP. Case Presentation: An 82-year-old male with a history of HT 26 years earlier underwent leadless pacemaker for recurrent syncope, deemed associated with conduction system disease. He had no history of cardiac allograft rejection, angiographic coronary allograft vasculopathy or left ventricular dysfunction. Six months post-implant he presented with shortness of breath and bilateral lower extremity edema. Management: Evaluation included: 1) Chest X-ray which was suggestive of pulmonary edema 2) natriuretic peptide level of 5,500 pg/ml (6-fold increase from 6 months prior) 3) echocardiogram showing EF of 69%, and 4) bilateral lower extremity Doppler ultrasound where he was found to have a large AVF between the right superficial femoral artery and superficial femoral vein. Subsequent right heart catheterization was notable for a PCWP of 18 mmHg and a cardiac output/index of 11 L/min and 5.8 L/min/m2 respectively, hence confirming HOHF. Treatment with intravenous diuretic was initiated and percutaneous stent placement to correct the AVF was performed with symptomatic relief. Conclusion: This case highlights the rare but serious complication of unrecognized AVF following leadless pacemaker implant. Given that this event occurred in a HT recipient, a more exhaustive work-up was required to rule-out expected causes of congestion. To our knowledge there is only one other case report describing AVF post-LP implant for which no intervention was performed due to absence of symptoms at 6-month follow up and HOHF was not reported. Our case emphasizes that the differential diagnosis of new onset of signs and symptoms of heart failure that develop post LP implant in general and in HT recipients specifically, should include HOHF related to an unrecognized procedural AVF.