The impact of volume reduction on early and long-term outcomes in surgical ventricular restoration for severe heart failure

Clinical and hemodynamic outcomes of the Dor procedure in adults with ischemic cardiomyopathy

Ischemic cardiomyopathy continues to be a major contributor to congestive heart failure, which places a significant burden on our healthcare system. Improving medications and different coronary revascularization strategies are the mainstays in the management of ischemic cardiomyopathy. Although medications and mechanical circulatory support are playing an ever-increasing role, cardiac transplantation remains the gold standard for treating advanced heart failure. Given the small number of available and suitable donor hearts, transplantation is limited for the majority of patients. Surgical ventricular restoration has repeatedly been suggested as a viable alternative in managing heart failure in select patients, as it is believed that surgically returning the ventricle to its original dimensions is possible and associated with favorable outcomes. The purpose of this manuscript is to comprehensively review the current literature on various surgical strategies for ventricular restoration. We also contextualize the published data with respect to ventricular function, volume, structure, arrhythmias, mitral regurgitation, and clinical outcomes.

Long-Term Results of Hybrid Left Ventricular Reconstruction in the Treatment of Ischemic Cardiomyopathy

The evidence supporting surgical aneurysmectomy in ischemic heart failure is inconsistent. The aim of the study was to describe long-term effect of minimally invasive hybrid transcatheter and minithoracotomy left ventricular (LV) reconstruction in patients with ischemic cardiomyopathy. Twenty-three subjects with transmural anterior wall scarring, LV ejection fraction 15–45%, and New York Heart Association class ≥ II were intervened using Revivent TC anchoring system. LV end-systolic volume index was reduced from 73.2 ± 27 ml at baseline to 51.5 ± 22 ml after 6 months (p < 0.001), 49.9 ± 20 ml after 2 years (p < 0.001), and 56.1 ± 16 ml after 5 years (p = 0.047). NYHA class improved significantly at 5 years compared to baseline. Six-min walk test distance increased at 2 years compared to the 6-month visit. Hybrid LV reconstruction using the anchoring system provides significant and durable LV volume reduction during 5-year follow-up in preselected patients with ischemic heart failure.

Ventricular volume and myocardial viability, evaluated using cardiac magnetic resonance imaging, affect long-term results after surgical ventricular reconstruction

OBJECTIVES

We aimed to investigate the outcomes of surgical ventricular reconstruction (SVR) for ischaemic cardiomyopathy and to identify ideal candidates for this procedure using cardiac magnetic resonance imaging (MRI) studies.

METHODS

We retrospectively examined 50 patients who underwent SVR and were preoperatively evaluated using cardiac MRI from 2004 to 2014. Cine MRI and gadolinium-enhanced MRI were performed to evaluate left ventricular (LV) volume and scarring. The midterm (median, 2.5 years) risk factors of cardiac death or major adverse cardiac events (MACEs) were analysed. Patients were divided into three groups-those with preoperative indexed LV end-systolic volume (LVESVI) of ≤100 ml/m² (Group 1), those with LVESVI of >100 and ≤130 ml/m² (Group 2) and those with LVESVI of >130 ml/m² (Group 3)-and examined.

RESULTS

In total, 17 patients exhibited MACEs at follow-up. Kaplan-Meier analysis showed that the 5-year rate of freedom from MACEs was 66%. The Cox hazard model indicated that preoperative LVESVI was the only significant predictor for MACEs (P = 0.006; hazard ratio, 1.02; 95% confidence interval, 1.01-1.04). Moreover, a significant reduction in LVESVI and an increase in LV ejection fraction (LVEF) were observed early after SVR (preoperative versus postoperative: LVESVI, 110 ± 44 vs 68 ± 28 ml/m², P < 0.001; LVEF, 24.3 ± 10.3 vs 32.0 ± 10.4%, P < 0.001) and at follow-up (LVESVI, 61 ± 28 ml/m², P < 0.001; LVEF, 36.5 ± 11.5%, P < 0.001). Although no difference was observed between the groups at follow-up, LVEF and LVESVI primarily improved in Group 2. LVEF improvement was significantly greater in Group 2 than in Group 1 (%increase in LVEF: Group 1, 6%; Group 2, 18%; P = 0.008). In patients with a preoperative LVESVI of >130 ml/m², the number of non-viable segments was a significant risk factor for MACEs.

CONCLUSIONS

Patients with preoperative LVESVI ranging from 100 to 130 ml/m² had fairly better outcomes, and the percentage improvement in LVEF and the percentage reduction in LVESVI were more pronounced in these patients. Hence, accurate preoperative assessments of LV volume and viability testing using cardiac MRI studies are essential for better stratification of the SVR procedure.

Personalized surgical repair of left ventricular aneurysm with computer-assisted ventricular engineering

OBJECTIVES

Although circular ventricular resection techniques are the gold standard of left ventricular (LV) restoration, these techniques can lead to suboptimal results. Postoperative systolic resection can be inadequate, because it must be planned on a heart stopped in diastole. Low cardiac output due to insufficient LV volume results in a potentially unstable condition, and cannot be corrected. Our aim was to find a preoperative method to minimize risk and maximize outcome with ventricular restoration.

METHODS

We created a novel method combining surgery with gadolinium-enhanced magnetic resonance to construct a preoperative 3D systolic heart model. The model was utilized to determine resection points that could be intraoperatively used. According to our calculations with the predetermined resection line, the calculated percentage reduction in LV volume was above 30%, and LV volumes were predicted above normal values; thus, performing the operation using these resection points is likely to be safe and effective. We had a mixed, real-life patient group: mitral insufficiency or pulmonary hypertension were not exclusion criteria.

RESULTS

Forty-one procedures (12 concomitant mitral valve plasty) were done on consecutive patients in a single-centre experience. The incidence rate of major adverse clinical events was 32% postoperatively (n = 13). Control MRI showed a significant improvement in ejection fraction (18.3 ± 4.3 vs 31.3 ± 3.3; P = 0.04). All patients improved their New York Heart Association (NYHA) class postoperatively (40 patients NYHA III/IV versus 40 NYHA I/II). During long-term follow-up, 1 patient died due to end-stage heart failure.

CONCLUSIONS

Using this model, we were able to find the optimal resection line providing an excellent postoperative result, thus minimizing the risk of low cardiac output syndrome.

Analysis of patient-specific surgical ventricular restoration: importance of an ellipsoidal left ventricular geometry for diastolic and systolic function

Surgical ventricular restoration (SVR) is a procedure designed to treat heart failure by surgically excluding infarcted tissues from the dilated failing left ventricle. To elucidate and predict the effects of geometrical changes from SVR on cardiac function, we created patient-specific mathematical (finite-element) left ventricular models before and after surgery using untagged magnetic resonance images. Our results predict that the postsurgical improvement in systolic function was compromised by a decrease in diastolic distensibility in patients. These two conflicting effects typically manifested as a more depressed Starling relationship (stroke volume vs. end-diastolic pressure) after surgery. By simulating a restoration of the left ventricle back to its measured baseline sphericity, we show that both diastolic and systolic function improved. This result confirms that the increase in left ventricular sphericity commonly observed after SVR (endoventricular circular patch plasty) has a negative impact and contributes partly to the depressed Starling relationship. On the other hand, peak myofiber stress was reduced substantially (by 50%) after SVR, and the resultant left ventricular myofiber stress distribution became more uniform. This significant reduction in myofiber stress after SVR may help reduce adverse remodeling of the left ventricle. These results are consistent with the speculation proposed in the Surgical Treatment for Ischemic Heart Failure trial (20) for the neutral outcome, that "the lack of benefit seen with surgical ventricular reconstruction is that benefits anticipated from surgical reduction of left ventricular volume (reduced wall stress and improvement in systolic function) are counter-balanced by a reduction in diastolic distensibility."