Extra-aortic balloon counterpulsation: an intraoperative feasibility study.

BACKGROUND: Current methods of counterpulsation or ventricular assistance have significant vascular and limb complications. The aim of this study was to determine the safety and performance of a new method of non-blood-contacting counterpulsation using an inflatable cuff around the ascending aorta (extra-aortic balloon [EAB]). METHODS AND RESULTS: In 6 patients undergoing first time off-pump coronary bypass surgery via sternotomy, the EAB was secured around the ascending aorta and attached to a standard counterpulsation console. At baseline and with 1:2 and 1:1 augmentation, hemodynamic and echocardiographic parameters of ventricular function and coronary flow were measured. High-intensity transient signals were measured using transcutaneous Doppler over the right common carotid artery. No complications occurred. With EAB there was no significant change in heart rate or blood pressure and no increase in high-intensity transient signals. There was a 67% increase in diastolic coronary blood flow (mean left-main diastolic velocity time integral 15.3 cm unassisted versus 25.1 cm assisted, P<0.05). Measurements with transesophageal echocardiography at baseline and with 1:1 counterpulsation demonstrated a 6% reduction in end-diastolic area (P=NS), a 16% reduction in end-systolic area (P<0.01), a 31% reduction in left ventricular wall stress (P<0.05), and a 13% improvement in fractional area change (P<0.005). CONCLUSIONS: EAB counterpulsation augments coronary flow and reduces left ventricular afterload. Further testing is warranted to assess the use of the EAB for chronic non-blood-contacting support of the failing heart.

Ambulatory extra-aortic counterpulsation in patients with moderate to severe chronic heart failure.

OBJECTIVES: The study sought to assess feasibility, safety, and potential efficacy of a novel implantable extra-aortic counterpulsation system (C-Pulse) in functional class III and ambulatory functional class IV heart failure (HF) patients. BACKGROUND: 30% to 40% of HF patients suffer from poor functional status and quality of life (QoL) but are not in need of end-stage treatments. We undertook a multicenter single-arm study to assess the C-Pulse System in such patients. METHODS: New York Heart Association (NYHA) functional class III or ambulatory functional class IV HF patients were eligible. Safety was assessed continuously through 12 months. Efficacy measurements included changes from baseline to 6 and 12 months in NYHA functional class, Minnesota Living with Heart Failure (MLWHF) and Kansas City Cardiomyopathy Questionnaire (KCCQ) scores, 6-min walk distance (6MWD), and exercise peak oxygen consumption (pVO2; 6 months only). RESULTS: Twelve men and 8 women (56.7 ± 7 years, 34 to 71 years of age) with ischemic (n = 7) or nonischemic (n = 13) cardiomyopathy were implanted. There was no 30-day mortality and no neurological events or myocardial infarctions through 12 months. At 6 months, there were 3 deaths (1 device-related). One-year survival was 85%. At 6 months, C-Pulse produced improvements in NYHA functional class (3.1 ± 0.3 to 1.9 ± 0.7, p = 0.0005), MLWHF (63.6 ± 19.9 to 40.2 ± 23.2, p = 0.0005), and KCCQ scores (43.6 ± 21.1 to 65.6 ± 21.5, p = 0.0002), but not 6MWD (275.5 ± 64.0 to 296.4 ± 104.9, p = NS) or pVO2 (14.5 ± 3.6 to 13.1 ± 4.4, p = NS). Improvements continued at 12 months, with 6MWD change becoming statistically significant (336.5 ± 91.8, p = 0.0425). CONCLUSIONS: Use of C-Pulse in this population is feasible, appears safe, and improves functional status and QoL. A prospective, multicenter, randomized controlled trial is underway. (C-Pulse IDE Feasability Study-A Heart Assist System; NCT00815880).

Chronic extra-aortic balloon counterpulsation: first-in-human pilot study in end-stage heart failure.

BACKGROUND: Some patients continue to have significant heart failure symptoms despite optimal medical therapy. METHODS: We describe a first-in-human experience with an implantable non-blood-contacting extra-ascending aortic counterpulsation heart assist system (C-Pulse) in 5 end-stage heart failure patients, aged 54 to 73 years. RESULTS: All patients improved by 1 NYHA class and improvements in invasive hemodynamics were documented in 3 patients. Three of 5 patients (60%) had infectious complications. Two patients were explanted at 5 and 7 weeks, respectively, as a result of mediastinal infection related to the implant procedure. One patient was successfully transplanted at 1 month and 1 remained hemodynamically improved on the device at 6 months but suffered infective complications. The device and protocol have been modified as a result of this pilot study with a further multicenter safety study underway. CONCLUSIONS: Although feasibility of this device is suggested by this pilot study, safety and efficacy will need to be examined in a larger cohort with longer follow-up.

Extra-aortic implantable counterpulsation pump in chronic heart failure.

Extra-aortic counterpulsation for the management of chronic heart failure is a novel approach. We report the use of an extra-aortic implantable counterpulsation pump in the management of a 73-year-old patient with severe heart failure refractory to medical therapy. The implantable counterpulsation pump prolonged his life and greatly improved its quality. The patient lived almost 7 months after the implantation of the device and died of septic complications secondary to gas line infection.

Extra-ascending aortic versus intra-descending aortic balloon counterpulsation-effect on coronary artery blood flow.

BACKGROUND: Diastolic counterpulsation has been used to provide circulatory augmentation for chronic heart failure or for short-term cardiac support. Recently an extra-aortic balloon (EAB) counterpulsation device has been proposed. AIM: To compare the circulatory effects of counterpulsation using the EAB or an intra-aortic balloon (IAB) in the acute pig model. METHODS: In six anaesthetized great white pigs (paced at 100 bpm), ECG, arterial and central venous pressures, flow in the coronary circulation and descending thoracic aorta were measured. Baseline data was collected, then with the EAB or an IAB fitted using 1:1 and 1:2 counterpulsation modes. Baseline data was compared to EAB and IAB data in 1:1 mode. Assisted beat data compared to unassisted beat data was also analysed in 1:2 mode. RESULTS: Both devices augmented peak diastolic arterial pressure, and decreased afterload. EAB counterpulsation increased diastolic coronary flow in both the 1:1 mode by 69% (p < 0.05) and in the 1:2 mode by 63% (assisted versus unassisted beat, p < 0.05). The IAB significantly increased diastolic coronary flow only in the 1:2 mode by 28% (p < 0.01). Both devices augmented total coronary flow and some augmentation of aortic flow was observed. CONCLUSION: The circulatory effect of the EAB and IAB counterpulsation were comparable. This suggests the EAB could be used as a non-blood contacting heart assist device in patients suffering moderate-severe heart failure.