S. Lalonde

Clinical Differences Between Continuous Flow Ventricular Assist Devices: A Comparison Between HeartMate II and HeartWare HVAD

The HeartWare ventricular assist device (HVAD) is a new generation centrifugal flow VAD recently introduced in Canada. The objective of this study was to compare the HVAD device to the HeartMate II (HMII) axial flow device. Very few studies have compared clinical outcomes between newer generation VADs.

Changes in Circulating Progenitor Cells Are Associated With Outcome in Heart Failure Patients: A Longitudinal Study

BACKGROUND Circulating progenitor cells (CPCs) are involved in the process of endothelial repair and are a prognostic factor in cardiovascular diseases. We evaluated the association between serial measurements of CPCs and functional capacity and outcomes in heart failure (HF). METHODS We included 156 consecutive consenting ambulatory HF patients (left ventricular ejection fraction < 40%). We evaluated CPCs and functional capacity (peak VO2) every 6 months for up to 2 years. CPCs were measured as early-outgrowth colony-forming units (EO-CFUs) and circulating CD34+, VEGFR2+ and/or CD133+ cells. We recorded mortality, HF hospital admissions, transplant, and ventricular assist device. RESULTS The mean age was 55 ± 15 years. A decrease in CD34+VEGFR2+ cells was independently associated with increased functional capacity; a 10-cell decrease in CD34+VEGFR2+ cells was associated with an increase of 0.2 mL/kg/min in peak VO2 (P < 0.05). We found an interaction effect (P = 0.02) between EO-CFUs and diabetes: in patients without diabetes, a 10-EO-CFU increase was independently associated with increased peak VO2 of 0.28 mL/kg/min (P = 0.01), and in patients with diabetes, a decrease in EO-CFUs was associated with an increased peak VO2 (P < 0.05). Higher EO-CFUs were associated with reduced mortality (hazard ratio, 0.25; 95% confidence interval, 0.09-0.69). CONCLUSIONS We noted differential relations between CPCs and outcomes in patients with vs without diabetes. Higher EO-CFUs and lower CD34+VEGFR2+ cells were associated with improved functional capacity and reduced mortality in nondiabetic patients. In patients with diabetes, lower EO-CFUs were associated with improved functional capacity. The basis for these differences requires further examination.

Increased cyclic guanosine monophosphate levels and continuous-flow left-ventricular assist devices: Implications for gastrointestinal bleeding

OBJECTIVES We examine the hypothesis that cyclic guanosine monophosphate (cGMP) levels are elevated in recipients of continuous-flow left ventricular assist devices (CF-LVADs) and that elevated cGMP levels are associated with a risk of gastrointestinal (GI) bleeding events. METHODS The levels of cGMP, nitric oxide, platelet activation markers, platelet-derived growth factors (PDGF) AB/BB and AA, and the inflammatory mediator C-reactive protein (CRP) were examined in 19 CF-LVAD recipients, 21 patients who had heart failure, and 19 healthy control-group participants. RESULTS The median level of cGMP was significantly higher in CF-LVAD recipients, compared with healthy participants (6.6 vs 2.1 pmol/mL, u = 62.5; P = .001; r = -0.55). Median cGMP levels in the heart failure group (12.5 pmol/L) were higher, compared with both CF-LVAD recipients (u = 75.0; P = .001; r = -0.53) and healthy participants (u = 4.0; P < .001; r = -0.83). Compared with the healthy group, median CRP levels were significantly higher in CF-LVAD recipients (2.9 vs 8.0 mg/L; u = 58.0; P < .001; r = -0.63) and heart failure patients (2.9 vs 7.0 mg/L; u = 59.0; P < .001; r = -0.65). In the subgroup of patients supported with the HeartMate II (Thoratec Corporation, Pleasanton, Calif), pulsatility index was significantly negatively correlated with cGMP levels (r = -0.73; P < .05), indicating that low pulsatility index is associated with higher cGMP levels. High cGMP levels were significantly associated with GI bleeding events, but not with bleeding events in general. CONCLUSIONS The primary finding of this study is that GI bleeding in CF-LVAD recipients is associated with significantly elevated cGMP levels, despite high levels of CRP, which interfere with cGMP production. Further studies are required to determine whether elevated cGMP levels can be used as a clinical marker for increased risk of GI bleeding in CF-LVAD recipients.

131 Endothelial progenitor cells and functional capacity in heart failure patients

BACKGROUND: Prompt access to care that optimizes outcomes is crucial in the management of heart failure (HF). The Canadian Cardiology Society (CCS) recommends that patients should be seen within two weeks following an emergency department (ED) visit for HF. However, it is unknown whether lack of adherence to this benchmark translates into worse clinical outcomes. OBJECTIVE: The objective was to examine whether delay in consultation following an ED visit for HF was related to adverse outcomes/events (death, hospitalization or repeat ED visit). METHODS: Patients with a confirmed diagnosis of HF were recruited by nurses at 8 hospital EDs in Quebec, Canada. They were interviewed by telephone within 6 weeks of ED discharge and subsequently at 3 months and 6 months. They responded to questions related to use of health services, sociodemographic information, the Minnesota Living with Heart Failure Questionnaire, and the Stanford Self-Efficacy in Chronic Disease Questionnaire. Pertinent clinical variables were extracted from medical charts by trained nurses. We used Cox regression to analyze whether delayed medical follow-up following ED visit was associated with increased risk of adverse events independently of other clinical covariates. RESULTS: We recruited a total of 551 patients. The mean age was 75.5 11.0 years and 51% were males. Only 30% consulted with a physician for their HF within 2 weeks post ED visit. By 4 weeks, 51% consulted a physician. Over the 6 month follow-up, 25% returned to the ED, 23% were hospitalized, and 13.6% died. Patients who consulted a physician within 2 weeks of ED discharge had a non-significantly lower risk of adverse events (HR: 0.69, 95% CI 0.40-1.2). However, by 4 weeks, this relationship became statistically significant: patients who consulted a physician for their HF within 4 weeks were less likely to sustain an adverse event (HR: 0.59, 95% CI 0.36-0.97). In addition to late clinical follow up, factors associated with a higher risk of adverse event included worse Minnesota Score, HF with systolic dysfunction and previous myocardial infarction. CONCLUSION: Prompt follow-up post ED visit for HF is associated with lower risk for major adverse event. Adherence to current CCS benchmarks is crucial. There is an urgent need to improve the rate of medical consultation within 2 to 4 weeks following ED visit for patients with HF. Canadian Institutes of Health Research (CIHR)