Partial left ventriculectomy: the 2nd International Registry Report 2000

Partial left ventriculectomy--The Third International Registry Report 2002

BACKGROUND

An international registry of partial left ventriculectomy (PLV) has been expanded, updated, and refined to include 440 cases voluntarily reported from 51 hospitals in 11 countries.

RESULTS

Gender, age, ventricular dimension, etiology, ethnology, myocardial mass, operative variation or presence or absence of mitral regurgitation as well as transplant indication had no effects on event-free survival, which was defined as either absence of death or ventricular failure requiring ventricular assist device or listing for transplantation. Preoperative patient condition such as NYHA functional class IV, depressed contractility, and decompensation requiring an emergency procedure were associated with reduced event-free survival. Other risk factors included early date of surgery, lack of experience, and extended myocardial resection. Performance of PLV reached a peak by 1998 and was largely abandoned by 2000 except in Asia, where experienced institutes continue to perform PLV in patients in better condition with preserved myocardial contractility.

CONCLUSION

Avoidance of delineated risk factors appears to improve recent survival and may help stratify high- or low-risk patients for PLV. An integrated approach with mechanical and biological circulatory assist may improve prognosis for patients with dilated failing hearts. While frequency of PLV has decreased, the concept of ventricular volume reduction has been extended to other volume reduction procedures and less invasive procedures now under clinical trial.

Does repair of mitral regurgitation eliminate the need for left ventricular volume reduction?

BACKGROUND

Effects of partial left ventriculectomy (PLV) remain ill-defined because mitral regurgitation (MR) repair by isolated annuloplasty alone has been reported to improve patients with dilated left ventricle and severe MR.

METHODS

Among patients undergoing PLV, 120 had paired pre- and postoperative (<1 week) Doppler echocardiograms. Effects of preoperative MR were studied by comparing 45 patients with no preoperative MR (MR-) and 75 patients with significant MR (MR+; MR = 1.51 when MR is enumerated as none = 0, mild = 1, moderate = 2).

RESULTS

MR- patients as compared with the MR+ group were older (53.8 vs. 49.2 years, P = 0.047), had less frequent dilated cardiomyopathy (33.3% vs 49.3%,P <0.01), similar ventricular dimension (72.3 mm vs 73.0 mm), septal thickness (9.5 mm vs 9.6 mm), posterior wall, fractional shortening (15.9% vs 16.8%) and ventricular mass (330 g vs 345 g), resulting in comparably reduced functional capacity (NYHA 3.40 vs 3.67). Although the MR- group required significantly less frequent mitral procedure (64.4% vs 84.0%, P < 0.01) and shorter cardiac arrest time, they had similar postoperative MR (0.22 vs 0.39), highly significant parallel reduction in ventricular dimension (P < 0.001 in either group), and improved %FS (P <0.001 in either group), resulting in similar hospital survival (87.1% vs 86.4%) and 90-day survival (71.1% vs 78.7%) with significantly comparable improvement in functional class (P = 0.011 in both groups). Histological severity of interstitial fibrosis (P = 0.80), weight (P = 0.93), and thickness (P = 0.76) of excised myocardium was comparable between the two groups.

CONCLUSION

Patients with no preoperative MR were found to benefit from PLV as did patients with significant MR. Beneficial effects of PLV appeared to derive mainly from volume reduction rather than abolished MR in this study.

Partial left ventriculectomy in pediatric end-stage dilated cardiomyopathy

OBJECTIVE

Although a recent survey on pediatric cardiomyopathy in Japan showed that 48% of patients died despite the medical treatment, pediatric cardiac transplantation is not legal in Japan. We determined the feasibility of partial left ventriculectomy as an alternative to end-stage dilated cardiomyopathy.

METHOD

We retrospective analyzed partial left ventriculectomy in 4 pediatric patients with end-stage dilated cardiomyopathy.

RESULTS

In case 1, an 8-month-old girl underwent semiemergency partial left ventriculectomy. Her ejection fraction increased from 10% to 25%, and her condition improved initially, but she developed heart failure and underwent cardiac transplantation 6 months later in the US. In case 2, a 3-year-old boy developed severe heart failure 2 months after ventricular septal defect repair. Intensive medical therapy failed, so partial left ventriculectomy was done, which increased his ejection fraction from 15% to 35%. His condition is stable 35 months after surgery. In case 3, a 2-year-old girl with a chromosomal anomaly undergoing ventricular septal defect repair developed progressive heart failure 1 year later. Despite emergency partial left ventriculectomy, she died of hemoptysis 2 weeks postoperatively. In case 4, a 2-year-old girl developing progressive heart failure unresponsive to medical therapy after 10 months underwent elective partial left ventriculectomy and remains in stable condition 18 months postoperatively.

CONCLUSION

Partial left ventriculectomy is appropriate for selected patients with end-stage dilated cardiomyopathy if medical therapy is not effective and heart transplantation is not possible.

Indications for partial left ventriculectomy in pediatric dilated cardiomyopathy

The purpose of this study was to define the role and indications of partial left ventriculectomy (PLV) in children with end-stage dilated cardiomyopathy (DCM). Clinical data were collected by retrospective chart review of children with DCM who were treated from 1997 to 2000. Four patients underwent PLV (PLV group) and 5 patients were managed without PLV (non-PLV group). In the PLV group, 2 patients are well 18 and 35 months postoperatively. One infant survived 6 months and then successfully underwent heart transplantation, and the other child died of hemoptysis 2 weeks postoperatively. Factors affecting outcome were preoperative status, in particular whether surgery was performed urgently or electively. In the non-PLV group, 4 patients were well controlled by medical treatment and 1 infant underwent mitral valve replacement for severe mitral regurgitation. The cardiothoracic ratio ranged from 72% to 76% in the PLV group and from 45% to 60% in the non-PLV group. The percentage of the expected left ventricular diastolic dimension ranged from 184% to 218% in the PLV group and from 109% to 163% in the non-PLV group. Ejection fractions in the PLV group were from 10% to 22% and from 36% to 56% in the non-PLV group. The serum brain natriuretic peptide concentration was above 1,200 pg/ml in the PLV group and below 168 pg/ml in the non-PLV group. In conclusion, PLV is indicated for selected children with end-stage DCM, and is most appropriate when medical therapy is not effective and heart transplantation is unavailable.

Partial left ventriculectomy for patients with ischemic cardiomyopathy

BACKGROUND

Partial left ventriculectomy (PLV) has been performed in patients with dilated cardiomyopathy (DCM), but improved myocardial energetics may make PLV useful also for ischemic cardiomyopathy (ICM) unamenable to conventional treatment.

METHODS

Of 262 patients undergoing PLV, 94 patients with ICM as the underlying pathology were analyzed and compared with 168 patients with DCM.

RESULTS

ICM patients were older (57.3 years vs 50.9 years, p = 0.0001) and heavier (69.7 kg vs 65.9 kg, p = 0.039) than those with DCM, but ventricular end-diastolic and end-systolic dimensions were similar with comparably depressed fractional shortening (16% vs 15%, p = 0.294) and equally severe functional limitation [New York Heart Association (NYHA) Class 3.7 vs 3.6, p = 0.734]. A majority of patients in both groups underwent lateral PLV (76% vs 74%, p = 0.883) with myocardium excised between papillary muscles and simultaneous mitral valvuloplasty (41% vs 74%, p < 0.0001). Because ICM patients required coronary artery bypass grafting (CABG) more frequently (79% vs 0.6%, p < 0.0001), operation was more extensive in terms of bypass time (74 minutes vs 47 minutes, p < 0.0001), percentage requiring cardiac arrest (43% vs 19%, p < 0.0001), and arrest duration (34 minutes vs 28 minutes, p = 0.280), but all had similar resection and postoperative ventricular dimensions. Nonetheless, ICM patients required shorter intensive care unit (ICU) time (4.4 days vs 5.9 days, p = 0.048) and similar postoperative hospital stays, resulting in similar hospital survival rates (69% vs 71%, p = 0.778) and functional capacity in long-term follow-up.

CONCLUSIONS

Results suggest that PLV can be performed in patients with ICM with comparable risks and benefits as in DCM. Relative efficacy of CABG and mitral repair as compared to volume reduction remains to be studied.

Partial left ventriculectomy: history, current status, and future role

Whereas discouraging clinical results and lack of scientific evidence decreased the initial interest in partial left ventriculectomy (PLV), factors contributing to success and failure have now been identified by clinical observations, theoretical analyses, and data from an international registry, which are herein reviewed to outline the current status and future role of this procedure as a treatment of heart failure.

Histopathology of resected myocardium and outcome of partial left ventriculectomy

BACKGROUND

Since preoperative hemodynamics are not proven to be a predictor of effects of partial left ventriculectomy (PLV), myocardial histopathology may be better correlated with effects and outcome of PLV.

METHODS

Myocyte size (micron) in the excised myocardium was measured in 338 patients undergoing PLV. Endocardial fibrosis, interstitial fibrosis, and inflammatory cell infiltration were enumerated as none = 0, mild = 1, moderate = 2, and severe = 3. These histopathologic observations were correlated with patients' postoperative survival.

RESULTS

Reduced survival was seen in patients with advanced (> or = moderate) interstitial fibrosis in all patients (n = 338, p = 0.064) and in the subgroup with nonischemic etiology (n = 229, p = 0.0039). Although correlation between endocardial and interstitial fibrosis was significant (r = 0.55, p < 0.01), endocardial fibrosis failed to correlate with postoperative survival. While Chagas' disease was associated with severe inflammation and poor survival, the presence of inflammatory cell infiltration had no effect on survival in all patients combined (p = 0.943). Although most patients (n = 266, 79%) had myocyte diameter over 30 micron, those with less hypertrophy (< 30 micron, n = 70, 21%) had a tendency toward increased survival (p = 0.067) regardless of underlying etiology.

CONCLUSION

Interstitial fibrosis may be an important factor in stratification of patients for repair (PLV) or replacement (transplantation). PLV may be more beneficial in patients with less hypertrophy, before develqpment of interstitial fibrosis. Endomyocardial biopsy might not predict the extent or variation in degree of interstitial fibrosis, which may be better evaluated by other metabolic or perfusion studies that measure overall myocardial histopathology and viability.

Perioperative hemodynamics in patients undergoing partial left ventriculectomy

OBJECTIVES

Effects of partial left ventriculectomy (PLV) were studied by analyzing perioperative hemodynamics with measurements of left ventricular (LV) pressure-volume (PV) relationships and thermodilution catheter measurements in the pulmonary artery.

METHODS

Between July and October 1996, 43 consecutive patients underwent PLV with and without mitral valvuloplasty with a thermodilution catheter and PV loop analysis immediately before and after surgery. Patients were 52+/-13 years and 67+/-13 kg, with reduced functional capacity (New York Heart Association 3.3+/-0.3) due to cardiomyopathy (24), ischemic disease (13), valvular disease (3), and Chagas' disease (3).

RESULTS

PLV required cardiopulmonary bypass for 44+/-24 minutes, with the heart arrested in 10 patients for 26+/-22 minutes for coronary artery bypass grafting (8), aortic valve replacement (2), and autotransplantation (2). Two patients failed to come off bypass, six died in the hospital and 35 (35 [81.4%] of 43) were discharged. Changes in PV loops included decreased end-diastolic and end-systolic volume, resulting in no change in stroke volume. Pulmonary artery wedge pressure decreased despite elevated end-diastolic pressure. Ejection fraction, end-systolic elastance (E-max), afterload recruitable stroke work, and volume intercepts all improved and resulted in similar stroke work with less energy expenditure (less PV area), thus improving myocardial energetic efficiency.

CONCLUSION

Results suggest that PLV improves systolic function but decreases diastolic compliance, which results in reduced net ventricular function immediately after surgery. Thus, immediate hemodynamic improvements appeared to derive from reduced severity in mitral regurgitation and perioperative load manipulation. Improved myocardial energetics may ameliorate LV function and improve the course of underlying myocardial disease.