Prevalence of asymptomatic and electrically undetectable intracardiac inside-out abrasion in silicon-coated Riata® and Riata® ST implantable cardioverter-defibrillator leads.

BACKGROUND: Recently, several cases of symptomatic and/or electrically detectable intracardiac inside-out abrasions in silicon-coated Riata® and Riata® ST leads have been described. However, the prevalence in asymptomatic patients with unremarkable implantable cardioverter defibrillator (ICD) interrogation is unknown. The aim of this study was to determine the prevalence of asymptomatic and electrically undetectable intracardiac inside-out abrasion in silicon-coated Riata® and Riata® ST leads. METHODS: All 52 patients with an active silicone-coated Riata® and Riata® ST lead followed up in our outpatient clinic were scheduled for a premature ICD interrogation and a biplane chest radiograph. When an intracardiac inside-out abrasion was suspected, this finding was confirmed by fluoroscopy. RESULTS: Mean time since implantation was 71 ± 18 months. An intracardiac inside-out abrasion was confirmed by fluoroscopy in 6 patients (11.5%). Mean time from lead implantation to detection of intracardiac inside-out abrasion was 79 ± 14 months. In all patients with an intracardiac inside-out abrasion, ICD interrogation showed normal and stable electrical parameters. Retrospectively, in 4 of these 6 patients, a coronary angiography performed 25 ± 18 months before diagnosis of intracardiac inside-out abrasion already showed the defect. Despite undetected intracardiac inside-out abrasion, 2 of these 4 patients experienced adequate antitachycardia pacing and ICD-shocks. ICD leads were replaced in all 6 patients. CONCLUSIONS: The prevalence of asymptomatic intracardiac inside-out abrasion in silicon-coated Riata® and Riata® ST leads is higher than 10% when assessed by fluoroscopy, and most intracardiac inside-out abrasions are not detectable by ICD interrogation.

Continuous flow left ventricular assist devices: a valid option for heart failure patients.

Recent outstanding clinical advances with new mechanical circulatory systems (MCS) have led to additional strategies in the treatment of end stage heart failure (HF). Heart transplantation (HTx) can be postponed and for certain patients even replaced by smaller implantable left ventricular assist devices (LVAD). Mechanical support of the failing left ventricle enables appropriate hemodynamic stabilisation and recovery of secondary organ failure, often seen in these severely ill patients. These new devices may be of great help to bridge patients until a suitable cardiac allograft is available but are also discussed as definitive treatment for patients who do not qualify for transplantation. Main indications for LVAD implantation are bridge to recovery, bridge to transplantation or destination therapy. LVAD may be an important tool for patients with an expected prolonged period on the waiting list, for instance those with blood group 0 or B, with a body weight over 90 kg and those with potentially reversible secondary organ failure and pulmonary artery hypertension. However, LVAD implantation means an additional heart operation with inherent peri-operative risks and complications during the waiting period. Finally, cardiac transplantation in patients with prior implantation of a LVAD represents a surgical challenge. This review summarises the current knowledge about LVAD and continuous flow devices especially since the latter have been increasingly used worldwide in the most recent years. The review is also based on the institutional experience at Berne University Hospital between 2000 and 2012. Apart from short-term devices (Impella, Cardiac Assist, Deltastream and ECMO) which were used in approximately 150 cases, 85 pulsatile long-term LVAD, RVAD or bi-VAD and 44 non-pulsatile LVAD (mainly HeartMateII and HeartWare) were implanted. After an initial learning curve, one-year mortality dropped to 10.4% in the last 58 patients.

Effects of high-intensity training on indices of ventilatory efficiency in chronic heart failure.

BACKGROUND: Measures of ventilatory inefficiency, such as the slope of the relation between ventilation and carbon dioxide production ((Equation is included in full-text article.)slope) and the oxygen uptake efficiency slope (OUES) have recently been shown to be strong prognostic markers in patients with heart failure. Little is known regarding the effects of exercise training on these indices. METHODS: Fifty heart failure patients (mean age = 55 ± 6 years, ejection fraction = 33 ± 6%) referred to a residential cardiac rehabilitation program were randomized to a 2-month high-intensity training program (n = 24) or to a control group (n = 26). Before and after the study period, maximal cardiopulmonary exercise testing was performed, and markers of ventilatory inefficiency were determined. RESULTS: Training increased peak oxygen uptake ((Equation is included in full-text article.); 23%), exercise time (29%), and peak workload (28%), whereas no changes were observed in controls (all P < .05 between groups). No differences were observed in the (Equation is included in full-text article.)slope in either group. However, the ventilatory equivalent for oxygen ((Equation is included in full-text article.)ratio) was reduced at matched work rates throughout exercise (P < .01). The OUES increased by 12% in the exercise groups (P = .003) and 4% in controls. At baseline, trained patients had an OUES that was 69% of the age-predicted value and this improved to 78% after training (P = .004). The change in OUES was significantly related to the change in peak (Equation is included in full-text article.)with training (r = 0.63, P = .001). CONCLUSION: High-intensity training resulted in marked improvements in exercise capacity in patients with heart failure. Training improved the OUES and reduced the (Equation is included in full-text article.)ratio, but the (Equation is included in full-text article.)slope was unchanged. Among measures of ventilatory inefficiency, the OUES may be more sensitive to training than the (Equation is included in full-text article.)slope.

Predictors of impaired heart rate recovery: a myocardial perfusion SPECT study.

BACKGROUND: Heart rate recovery (HRR) is an established prognostic predictor. However, a number of methodological issues have not been fully explored, including differences in HRR 1 versus 2 min after exercise termination, absolute versus relative HRR, and the impact of beta-blockers. DESIGN: Cross-sectional study. METHODS: Predictors of impaired absolute and relative HRR 1 (HRR-1, HRR-1%) and 2 min after exercise termination (HRR-2, HRR-2%), defined as their lowest quartiles, were assessed in 1667 patients undergoing cycle exercise myocardial perfusion single photon emission computed tomography, and measures of HRR were compared between patients undergoing myocardial perfusion single photon emission computed tomography with continued, discontinued, and without beta-blockers. RESULTS: Higher resting heart rate was an independent predictor of all measures of impaired HRR (P<0.001 for all). Lower peak heart rate was independently associated with impaired HRR-1, HRR-2, and HRR-2% (P<0.001 for all) but not HRR-1%. Higher summed rest score as a marker of scar and in part left ventricular dysfunction was an independent predictor of impaired HRR-1 (P = 0.010) and HRR-1% (P = 0.025) but not HRR-2 and HRR-2%, whereas lower stroke volume index was an independent predictor of slow HRR-2 (P = 0.004) and HRR-2% (P = 0.02) but not HRR-1 and HRR-1%. HRR-1 (P = 0.98) and HRR-2 (P = 0.86) were similar in patients with continued, discontinued, and without beta-blocker therapy. In contrast, HRR-1% (P = 0.01) and HRR-2% (P = 0.001) were faster in patients on beta-blockers than in the other groups. CONCLUSION: HRR-1 and HRR-2 as well as HRR-1% and HRR-2% reflect different pathophysiological processes. Relative but not absolute measures of HRR seem to be enhanced under beta-blockers.

Exercise capacity, physical activity patterns and outcomes six years after cardiac rehabilitation in patients with heart failure.

OBJECTIVE: To determine the short- and long-term effects of an intensive, concentrated rehabilitation programme in patients with chronic heart failure. DESIGN: Randomized controlled trial, with one-month and six-year evaluations. SETTING: Residential rehabilitation centre in Switzerland. SUBJECTS: Fifty patients with chronic heart failure, randomized to exercise or control groups. INTERVENTIONS: A rehabilitation programme lasting one month, including educational sessions, a low-fat diet, and 2 hours of individually prescribed exercise daily. MAIN MEASURES: Exercise test responses, health outcomes and physical activity patterns. RESULTS: Peak Vo(2) increased 21.4% in the exercise group during the rehabilitation programme (P<0.05), whereas peak Vo(2) did not change among controls. After the six-year follow-up period, peak Vo(2) was only slightly higher than that at baseline in the trained group (7%, NS), while peak Vo(2) among controls was unchanged. During long-term follow-up, 9 and 12 patients died in the exercise and control groups, respectively (P = 0.63). At six years, physical activity patterns tended to be higher in the exercise group; the mean energy expenditure values over the last year were 2,704 +/- 1,970 and 2,085 +/- 1,522 kcal/week during recreational activities for the exercise and control groups, respectively. However, both groups were more active compared to energy expenditure prior to their cardiac event (P<0.001). CONCLUSIONS: Six years after participation in a residential rehabilitation programme, patients with chronic heart failure had slightly better outcomes than control subjects, maintained exercise capacity and engaged in activities that exceed the minimal amount recommended by guidelines for cardiovascular health.

Maintenance of exercise capacity and physical activity patterns 2 years after cardiac rehabilitation.

BACKGROUND: The benefits of exercise training for postmyocardial infarction and postcoronary artery bypass surgery patients are well established, but little is known about the effects of rehabilitation in the months or years following the program. The purpose of this study was to assess exercise capacity, blood lipids, and physical activity patterns 2 years after completing a concentrated residential rehabilitation program in Switzerland. METHODS: Seventy-eight patients (86% males, mean age = 56 +/- 10, mean ejection fraction = 64% +/- 12%) were referred to a residential rehabilitation program after a myocardial infarction or coronary artery bypass surgery between January 2001 and June 2001. Patients lived at the center for 1 month, during which time they underwent educational sessions, consumed a low-fat diet, and exercised 2 hours daily. Two years after completing the program, patients returned to the hospital and underwent a maximal exercise test, an assessment of recent and adulthood physical activity patterns, and evaluation of blood lipids. RESULTS: During the 2-year follow-up period, there were 5 deaths, and 70 of the remaining 73 patients returned for repeat testing. Mean exercise capacity increased 27% during the rehabilitation program (P < .01). Gains in exercise capacity during rehabilitation were maintained after the follow-up period; mean exercise capacity after 2 years was 34% higher compared with that at baseline (P < .01). At the 2-year evaluation, patients were expending a mean of 3127 +/- 1689 kcals/wk during recreational activities compared with 977 +/- 842 kcals/wk during adulthood prior to their cardiac event (P < .001). Between the completion of rehabilitation and the 2-year follow-up, total cholesterol, total cholesterol/high-density lipoprotein ratio, and triglycerides increased significantly. CONCLUSIONS: Two years after a cardiac event and participation in a concentrated residential rehabilitation program, patients maintained their exercise capacity and engaged in physical activities that exceed the levels recommended by guidelines for cardiovascular health. These observations suggest that a relatively intensive rehabilitation program provided a catalyst to maintain physical activity patterns and exercise tolerance in the 2 years following a cardiac event.