Residency · Residency · Cardiothoracic Surgery

Surgical Management of Heart Failure Beyond LVAD and Transplant

Introduction

While left ventricular assist devices (LVADs) and heart transplantation remain the definitive surgical therapies for advanced heart failure, a substantial subset of patients are not candidates for these interventions or may benefit from alternative surgical approaches. This lecture examines surgical strategies that address the structural and functional derangements of the failing heart, including ventricular reconstruction, mitral valve surgery, cardiac restraint devices, and emerging regenerative therapies.

Pathophysiology of Surgical Heart Failure Targets

Ventricular Remodeling

Progressive LV dilation leads to spherical geometry, increased wall stress according to Laplace's law, and further dysfunction. Mitral annular dilation and papillary muscle displacement cause functional mitral regurgitation, creating a volume overload spiral. Myocardial fibrosis and scar from ischemic or non-ischemic insults reduce contractile reserve. Surgical interventions aim to restore ventricular geometry, reduce wall stress, correct valvular regurgitation, and improve hemodynamic efficiency.

Patient Selection

Thorough evaluation includes echocardiography, cardiac MRI with viability assessment, cardiopulmonary exercise testing, and right heart catheterization. Reversible contributions to heart failure such as ischemia, valvular disease, and dysrhythmia must be identified. Distinguishing between ischemic and non-ischemic etiologies is important because surgical options differ significantly. Patients who would be better served by LVAD or transplant listing should be excluded from alternative surgical strategies.

Surgical Ventricular Reconstruction

Rationale and History

Surgical ventricular reconstruction (SVR), also known as the Dor procedure, aims to exclude akinetic or dyskinetic scar tissue and restore elliptical LV geometry. Originally described by Dor in 1985 for post-infarction left ventricular aneurysms, the procedure reduces LV end-systolic volume index (ESVI), improves ejection fraction, and decreases wall stress.

Technique

SVR is performed on cardiopulmonary bypass with cardioplegic arrest. A ventriculotomy is made through the scar, and an endoventricular patch of Dacron or autologous tissue is placed to exclude non-viable myocardium. The target post-reconstruction ESVI is 50-60 mL/m2. The procedure is often combined with CABG for concomitant coronary artery disease and mitral valve repair.

Evidence and Current Role

The STICH trial (Hypothesis 2) showed no benefit of adding SVR to CABG in ischemic cardiomyopathy. However, critics argue that the trial did not achieve adequate volume reduction, with mean ESVI reduction of only 19%. Centers with expertise report favorable outcomes when strict selection criteria are applied, particularly for patients with large akinetic or dyskinetic segments and ESVI exceeding 80 mL/m2. SVR remains a reasonable option in highly selected patients at experienced centers.

Mitral Valve Surgery for Heart Failure

Functional Mitral Regurgitation

Functional mitral regurgitation is present in 30-50% of patients with dilated cardiomyopathy. The mechanism involves annular dilation and leaflet tethering from LV remodeling rather than intrinsic valve disease. It contributes to volume overload, pulmonary hypertension, and progressive ventricular dilation. Severity may fluctuate with loading conditions and medical therapy optimization.

Surgical Options

Undersized restrictive annuloplasty is the most common approach, reducing annular dimensions to restore coaptation. The ring size is typically downsized by 2 sizes, for example using a 26 mm ring for a 30 mm annulus. Subvalvular techniques include papillary muscle approximation, secondary chordal cutting, and posterior leaflet augmentation. Mitral valve replacement with chordal preservation is reserved for cases with severe tethering where coaptation depth exceeds 10 mm.

Evidence

The CTSN trial comparing repair versus replacement for severe ischemic mitral regurgitation showed higher recurrence rates with repair (32.6% versus 2.3% at 2 years) but no mortality difference. Repair is preferred for moderate MR at the time of CABG. Patient selection based on tethering geometry, LV dimensions, and likelihood of reverse remodeling is critical to achieving good outcomes.

Coronary Artery Bypass Grafting in Heart Failure

Viability-Guided Revascularization

CABG may improve outcomes in ischemic cardiomyopathy when viable but hibernating myocardium is present. Viability testing modalities include cardiac MRI (where late gadolinium enhancement transmurality below 50% predicts recovery), dobutamine stress echocardiography (assessing contractile reserve), and PET (evaluating metabolic-perfusion mismatch). The STICH trial (Hypothesis 1) demonstrated a long-term survival benefit of CABG plus medical therapy versus medical therapy alone in ischemic cardiomyopathy at 10-year follow-up. The greatest benefit occurs in patients with significant angina, multivessel disease, and preserved viability.

Technical Considerations

Complete revascularization is the goal, with use of arterial conduits where feasible. Off-pump CABG may reduce CPB-related inflammation in the fragile heart failure patient. Prolonged cross-clamp times should be avoided, and on-pump beating heart strategies may be considered for severely depressed LV function. Perioperative mechanical circulatory support with an intra-aortic balloon pump may be needed.

Cardiac Restraint and Support Devices

Passive Cardiac Restraint

The CorCap Cardiac Support Device is a polyester mesh placed around the ventricles to prevent further dilation. It was designed to halt remodeling rather than improve contractility. The Acorn trial showed reduction in LV dimensions but no mortality benefit, and the device is no longer commercially pursued. However, the concept validated the importance of addressing ventricular geometry in heart failure management.

Cardiac Contractility Modulation

Cardiac contractility modulation (CCM) delivers non-excitatory electrical signals during the absolute refractory period to enhance calcium handling and contractility. The Optimizer device is approved for NYHA class III heart failure with EF 25-45% and narrow QRS. While not a surgical implant in the traditional sense, it falls within the structural intervention category. The FIX-HF-5C trial demonstrated improvements in exercise tolerance and quality of life.

Emerging and Investigational Approaches

Cell-Based and Regenerative Therapies

Intramyocardial injection of stem cells, including mesenchymal and cardiac progenitor cells, during cardiac surgery has been investigated. Results to date have been modest, with improvements in scar size and regional function but inconsistent effects on global EF and clinical outcomes. Gene therapy targeting calcium handling through SERCA2a showed initial promise, but the phase 2b CUPID 2 trial was negative. Bioengineered cardiac patches and 3D-printed scaffolds are in early preclinical development.

Autonomic Modulation

Vagal nerve stimulation and baroreflex activation therapy aim to rebalance the autonomic nervous system in heart failure. The INOVATE-HF trial of vagal nerve stimulation did not improve outcomes, and optimal dosing and patient selection remain unclear. Splanchnic nerve modulation is a novel target under investigation for reducing cardiac filling pressures.

Key Clinical Pearls

Not all heart failure patients need or qualify for LVAD or transplant, and a tailored surgical approach addressing specific pathology such as ischemia, valve disease, or abnormal geometry may provide meaningful benefit. Viability assessment is essential before offering CABG to patients with ischemic cardiomyopathy and reduced EF. Functional MR surgery remains controversial, with high recurrence rates after repair, making patient selection based on tethering geometry critical. SVR should be reserved for experienced centers with careful patient selection, as the STICH trial's limitations do not invalidate the concept for well-selected patients. Regenerative therapies hold promise but have not yet demonstrated consistent clinical benefit in rigorous trials.

References

1. Jones RH, Velazquez EJ, Michler RE, et al. Coronary Bypass Surgery With or Without Surgical Ventricular Reconstruction. N Engl J Med. 2009;360(17):1705-1717.
2. Goldstein D, Moskowitz AJ, Gelijns AC, et al. Two-Year Outcomes of Surgical Treatment of Severe Ischemic Mitral Regurgitation. N Engl J Med. 2016;374(4):344-353.
3. Velazquez EJ, Lee KL, Jones RH, et al. Coronary-Artery Bypass Surgery in Patients With Ischemic Cardiomyopathy. N Engl J Med. 2016;374(16):1511-1520.
4. Mehra MR, Goldstein DJ, Cleveland JC, et al. Five-Year Outcomes in Patients With Fully Magnetically Levitated vs Axial-Flow Left Ventricular Assist Devices. JAMA. 2022;328(12):1233-1242.

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