Christopher T. Sparrow

Clinical outcomes associated with INTERMACS-defined right heart failure after left ventricular assist device implantation

Background: Left Ventricular Assist Device (LVAD) pump thrombosis (PT) is a devastating complication of mechanical circulatory support. The diagnosis of LVAD thrombus is difficult in vivo, often only suggested by markers of hemolysis and echocardiographic features, which lack sensitivity. We sought to test a probe with high avidity anti-fibrin 99mTc to localize and quantify thrombus within the high shear environment of titanium axial-flow pumps. Methods: Monomeric bifunctional ligands with a fibrin-specific peptide, a short spacer, and technetium chelating amino acid sequence (F1A) were covalently inter-coupled via a 4-arm-PEG2000 tetramer to form F4A. Each was radiolabeled with 99mTc using the IsoLink procedure. We collected 20 explanted HeartMate II LVADs, of which 9 were explanted for suspected pump thrombosis and 11 were explanted during heart transplant or exchange for other complications. Ex-vivo imaging of explanted pumps was conducted in plasma using a mock circulatory loop running at 9400 RPM for 30 minutes as has previously been described. After imaging the devices were sent to the manufacturer for disassembly and thorough inspection for thrombus. Results: The majority of patients were male (85%) with a mean age of 54.1 6 9.8 and a median INTERMACS profile of 2. The median time of LVAD support prior to explant was 7.6 6 7.2 months. Of the 9 patients exchanged for suspected pump thrombosis all had undetectable haptoglobin levels and mean LDH levels of 3520 6 2596. All 9 had CT scans prior to LVAD exchange without any visualized thrombus or kinking of the inflow or outflow cannulas. Two of the pumps have been disassembled and inspected by the manufacturer. Both pumps were in patients with suspected pump thrombosis and both the pumps had thrombus found on SPECT imaging and on visual inspection (Figure 1A and 1B). Conclusions: A novel, fibrin-specific 99mTc small tetrameric probe offers the potential to detect, localize, and quantify intra-LVAD thrombus noninvasively. Once verified in a large cohort this agent offers the opportunity to diagnose LVAD pump thrombosis at an earlier stage. Definite and early diagnosis may confer therapeutic options to avoid pump failure and/or costly and morbid LVAD exchange.

Repeat revascularisation outcomes after percutaneous coronary intervention in patients with rheumatoid arthritis

Objective To investigate repeat revascularisation outcomes in patients with rheumatoid arthritis(RA) after percutaneous coronary intervention (PCI). Methods We performed a single-centre, retrospective matched cohort study of patients with RA matched to non-RA patients post PCI. Primary endpoints were time to target lesion revascularisation (TLR) and target vessel revascularisation (TVR) analysed by Cox proportional hazard shared frailty models. Results A total of 228 lesions (143 patients) were identified in the RA cohort and matched to 677 control lesions (541 patients). TLR occurred in 33% (n=75) of RA lesions versus 25% (n=166) of control lesions (adjusted HR 1.3; 95% CI 0.97 to 1.8). TVR occurred in 39% (n=89) of RA lesions versus 31% (n=213) of control lesions (adjusted HR 1.15; 95% CI 0.82 to 1.6). There was a significant hazard for TLR (adjusted HR 1.48; 95% CI 1.03 to 2.13) and TVR (adjusted HR 1.55; 95% CI 1.12 to 2.14) when excluding lesions with revascularisation events or follow-up less than 1 year. When stratified by treatment with methotrexate or tumour necrosis factor (TNF) α inhibitors or both at discharge, lesions from patients with RA treated with these agents had similar TVR and TLR as control lesions, whereas lesions from patients with RA not treated with these agents had significantly more TLR and TVR (TLR adjusted HR 1.48; 95% CI 1.08 to 2.03; TVR adjusted HR 1.38; 95% CI 1.04 to 1.84). Conclusions RA predisposes to repeat revascularisation, specifically in patients followed after the 1-year landmark. In the absence of RA treatments including methotrexate and/or TNFα inhibitors, RA is associated with a 50% increased relative risk of repeat revascularisation following PCI. These findings emphasise the adverse effects of chronic inflammation on the durability of PCI and provide further support for aggressive anti-inflammatory treatment in patients with RA.

Intersection of Pulmonary Hypertension and Right Ventricular Dysfunction in Patients on Left Ventricular Assist Device Support: Is There a Role for Pulmonary Vasodilators?

Left ventricular assist devices (LVADs) improve survival and quality of life in patients with advanced heart failure. Despite these benefits, combined post- and precapillary pulmonary hypertension can be particularly problematic in patients on LVAD support, often exacerbating right ventricular (RV) dysfunction. Both persistently elevated pulmonary vascular resistance and RV dysfunction are associated with adverse outcomes, including death after LVAD. These observations have led to significant interest in the use of pulmonary vasodilators to treat pulmonary hypertension and preserve RV function among LVAD-supported patients. Although pulmonary vasodilators are commonly used for the treatment of pulmonary hypertension and RV dysfunction in LVADs, the benefits of this practice remain unclear. The purpose of this review is to highlight the current challenges in managing pulmonary vascular disease and RV dysfunction in patients with heart failure on LVAD support.

ECHO DERIVED RIGHT VENTRICULAR CONTRACTION PRESSURE INDEX PREDICTS RIGHT VENTRICULAR FAILURE AND MORTALITY IN PATIENTS WITH DURABLE LEFT VENTRICULAR ASSIST DEVICES

Right ventricular (RV) dysfunction is a major determinant of poor outcomes after continuous flow left ventricular assist device (CF-LVAD) implantation but can be difficult to evaluate prior to surgery. The simplified Right Ventricular Contraction Pressure Index (sRVCPI=TAPSE × RV-Right atrial