Extra-Aortic Balloon Counterpulsation

BY DR.VIJAYANAND PALANISAMY

HISTORY• Timed increase of the diastolic aortic pressure to augment coronary

flow was first demonstrated by the Kantrowitz brothers in 1953.

• First human trail of EABP done in may , 2005 – auckland city hospital , New zealand.

• Further experimental work using pedicled diaphragm wrapped around the descending aorta stimulated to contract during diastole demonstrated the added benefit of decreased ventricular work by lowering left ventricular afterload.

• An extra-aortic balloon (EAB) (C-Pulse; Sunshine Heart, Inc) has been developed for ascending aortic counterpulsation, which may be suitable for implantation in selected patients with heart failure who require ventricular assistance as destination therapy

• Assist the heart to pump rather than replacing the heart function

• designed to reduce clinical symptoms associated with moderate to severe (Class III/ambulatory Class IV) heart failure.

C-Pulse System Components

• The C-Pulse System includes a non-blood contacting cuff (polymer wrap) with polyurethane balloon, ECG sensing leads, Percutaneous Interface Lead (drive line), and an external driver (pump)

• Intraoperative animal studies have confirmed improved coronary blood flow with EAB counterpulsation, with no adverse histological effect on the ascending aorta after approximately 30 minutes of exposure.

Surgical Procedure• General anesthesia• Implantation was done through a standard median

sternotomy incision or minimally invasively through either a limited right parasternal thoracotomy procedure or via a hemisternotomy Approach

• significant diseases of the aortic root, valve, and ascending aorta were excluded

• An EAB cuff was placed around the ascending aorta (above sinotubular junction )and securely sutured into position

• The EAB was programmed to inflate at the dicrotic notch on the aortic pressure waveform and to deflate on the R wave of the ECG

Figure 1. Schematic of the extra-aortic balloon wrapped around the ascending aorta (a, deflated; b, inflated), showing “thumb printing” effect on the greater curve of the ascending

aorta.

Mechanism of Action

• The C-Pulse mechanism of action is based off the concept of counterpulsation. C-Pulse evolves this concept with the development of a chronic ambulatory circulatory support therapy that works by reducing left ventricular afterload during systole and augmenting blood pressure and systemic and coronary perfusion during diastole.

Supports Myocardial Perfusion

• The C-Pulse is positioned on the ascending aorta, the most elastic part of the arterial system.

• The ascending aorta acts as a reservoir for the heart to eject blood into. The inflation of the C-Pulse balloon during diastole creates a second pulse, increasing coronary flow and perfusion throughout the body.

Influence on Aortic Baroreceptors

• Using the intra-aortic balloon pump have shown hemodynamic effects which have been attributed to stimulation of baroreceptors in the aortic arch.¹’²

• The C-Pulse balloon placement on the aortic arch aligns anatomically with the aortic baroreceptors. In addition to direct mechanical compression, the rapid inflation and deflation during diastole and systole may provide optimal physiologic activation of these receptors. Activation of aortic baroreceptors has neuromodulatory effects resulting in reduction in sympathetic activity and increase in parasympathetic tone, reduced peripheral resistance and improvement in the kidney’s ability to excrete salt and water.

Effects on Left Ventricular Wall Stress

• Reducing arterial afterload in the ascending aorta leading to improved cardiac performance through increased velocity of shortening of the left ventricle.

• A reduction in left ventricular wall stress is also achieved while maintaining adequate coronary perfusion.

ADVANTAGE

• Improve cardiac function• Minimal invasive• No need of anticoagulants• Ambulant & Improve patient’s quality of life• Reduce re-hospitalizations due to heart failure

symptoms• Allow patients flexibility to disconnect for short periods

(< 15 minutes) of time if needed (e.g. personal hygiene)• Devoid of limb ischemia issues

Risk Related to the Investigational Device

• Lack of effect – insufficient relief from heart failure symptoms

• Device Failure• Aortic Rupture• Device–related Infection – Intra–thoracic and

Exit–site

CONTRAINDICATION

1. ascending aortic disease 2. aortic regurgitation (moderate-severe)3. intact aorto-coronary grafts.

• The C-Pulse System is implanted without any incisions on the heart itself or to any major vessels. In addition, the C-Pulse System may be used in combination with other approved devices for treating heart failure, such as a cardiac resynchronization device (CRT) or an implantable cardioverter defibrillator (ICD)

COUNTER HF Study

• Conducting in North America

• specific study criteria✓Class III or early Class IV heart failure

Ejection fraction ≤ 35%✓Taking appropriate HF medications as prescribed✓evaluated for cardiac resynchronization therapy ✓

(CRT) or an implantable cardioverter defibrillator (ICD)

THANK YOU