Prognosis of medically treated patients referred for cardiac transplantation

Should UNOS Status 2 Patients Undergo Transplantation?

BACKGROUND

With recent improvements in medical and device therapy, the benefit of cardiac transplantation for UNOS Status 2 patients has been questioned. No randomized trial has been performed to compare transplantation versus contemporary medical therapy.

METHODS

Between January 1996 and December 2003, 203 patients were listed at our institution for heart transplantation as UNOS Status 2. We performed a retrospective review to determine outcomes in these patients.

RESULTS

Demographics of this cohort revealed a mean age of 52 years, female sex in 28%, and ischemic etiology in 47%. Eighty-one patients (40%) had an implantable cardiac defibrillator. A total of 64 patients (32%) had to be upgraded in their UNOS status, with 9 requiring a left ventricular assist device. Of the entire group, 95 (47%) underwent transplantation at a mean time of 303 days, 45 (22%) died while waiting at a mean time of 397 days, and 24 (12%) were removed from the waiting list due to deterioration in medical condition such that transplantation was no longer an option. The remaining patients continue to wait or have been removed from consideration due to improved condition. Survival at 1- and 3-years postlisting was 94% and 87% for patients who received transplants compared to 81% and 57% for patients who did not receive transplants (P < .01).

CONCLUSION

A significant number of patients listed as Status 2 are upgraded in UNOS status or die while on the waiting list. Early and midterm survival is significantly better with transplantation. Identification of variables associated with deterioration may allow for better risk stratification in the future. At this point, transplantation offers the best outcome.

Determinants of Mortality in Patients Undergoing Cardiac Resynchronization Therapy: Baseline Clinical, Echocardiographic, and Angioscintigraphic Evaluation Prior to Resynchronization

BACKGROUND

In dilated cardiomyopathy (DCM) patients (pts) with cardiac resynchronization therapy (CRT) for ventricular dyssynchrony, long-term predictors of mortality and morbidity remain poorly investigated.

METHOD AND RESULTS

We reviewed data of 102 pts, 68 +/- 10 years, NYHA Class II-IV (14 Class II, 67 Class III, 21 Class IV), who benefited from CRT (69 CRT, 33 CRT-ICD). Fifty-two patients had an ischemic DCM, 36 a previously implanted conventional PM/ICD, 29 a permanent atrial fibrillation, and 19 needed dobutamine in the month preceding implant. QRS duration was 187 +/- 35 ms, left ventricular end-diastolic diameter 72 +/- 10 mm, mitral regurgitation severity 1.9 +/- 0.8, echographic aorto-pulmonary electromechanical delay 61.5 +/- 25 ms and septo-lateral left intraventricular delay 86 +/- 56 ms, pulmonary artery pressure (PAP) 43 +/- 11 mmHg, angioscintigraphic left ventricular ejection fraction (EF) 20 +/- 9%, and right ventricular EF 30.5 +/- 14%. Over a mean follow-up of 23 +/- 20 months, 26 pts died (18 heart failures (HFs), 1 arrhythmic storm, 7 noncardiac deaths). Positive univariate predictors of death from any cause were NYHA Class IV (P < 0.001), and need for dobutamine the month preceding CRT (P < 0.008), while use of beta-blocking agents (P < 0.08) and left ventricular EF (P < 0.09) were negative ones. NYHA Class IV was the only independent predictor at multivariate analysis (P < 0.01). Survival at 24 months was 85% in Class II, 80% in Class III, and 37% in Class IV (II vs III, P = ns; III vs IV, P < 0.001). When using a composite endpoint of death from any cause and unplanned rehospitalization for a major cardiovascular event, there were 48 events (14 HF deaths, 3 noncardiac deaths, 26 HF rehospitalizations, 2 paroxysmal atrial fibrillation, 2 sustained ventricular tachycardia, 1 nonfatal pulmonary embolism). Predictors of death from any cause/unplanned rehospitalization for a major cardiovascular event in the follow-up were NYHA Class IV (P < 0.001), need for dobutamine during the month preceding CRT (P < 0.002), and PAP (<0.02). NYHA Class IV was the only independent predictor at multivariate analysis (P < 0.05). Event-free proportion at 24 months was 70% in Class II, 64% in Class III, and 37% in Class IV (II vs III, P = ns; III vs IV, P < 0.01). When considering determinants of mortality only in NYHA Class IV patients, no variable was significantly correlated to mortality. Need for dobutamine during the last month preceding CRT did not add an adjunctive mortality risk.

CONCLUSION

Baseline NYHA Class IV at implantation appears as the most important determinant of a poor clinical outcome in terms of both mortality and morbidity. No predictive criteria seem available for NYHA Class IV patients, in order to discriminate who will die after CRT and who will not. NYHA Class IV strongly influences the clinical outcome, suggesting that, in future studies planned on mortality and rehospitalization as major endpoints, baseline NYHA Class IV should be separately taken into account.

Should stable UNOS Status 2 patients be transplanted?

BACKGROUND

Improved outcomes with contemporary medical therapy in patients with advanced heart failure brings into question the survival advantage of transplantation for patients in stable United Network for Organ Sharing (UNOS) Status 2.

METHODS

Between January 1999 and June 2001, a total of 7,539 adult patients were listed for heart transplantation. Of those, 4,255 (56.4%) patients were listed as UNOS Status 2. Using a competing risk method, we computed probabilities of events while on the waiting list. Additionally, we used a time-dependent proportional hazards model to determine predictors of death before and after transplantation.

RESULTS

Demographics included age >60 (72%), female sex (23%), ischemic causes for transplantation (49%), white race (85%), and median time on the waiting list (544 days). Laboratory and hemodynamic values included mean serum albumin of 3.9 g/dl, serum creatinine of 1.4 mg/dl, mean pulmonary artery pressure of 28 mm Hg, mean pulmonary capillary wedge pressure of 19 mm Hg, and mean cardiac output of 4.5 liter/min. Final outcomes on the waiting list for patients initially listed as UNOS Status 2 were transplantation (48%), removal from the list (11.5%), death (11.4%), and continued listing (29%). At 30 months after transplantation, survival was 81% for patients undergoing transplantation as Status 1A, 77% as Status 1B, and 83% as Status 2, and showed no difference among groups. At 365 days, survival analysis showed no difference for patients listed and undergoing transplantation as UNOS Status 2 compared with those still waiting as Status 2.

CONCLUSION

In the current era of advances in medical and surgical therapies for heart failure, we found no survival benefit of cardiac transplantation at 1 year for patients initially listed as UNOS Status 2.

Noninvasive assessment of cardiac pumping capacity during exercise predicts prognosis in patients with congestive heart failure

BACKGROUND

Prognostic parameters in patients with congestive heart failure (CHF) are important for guiding therapeutic options. Maximal oxygen uptake (O(2)max) is a widely used parameter for prognostic assessment in patients with CHF and correlates with exercise cardiac output; however, afterload is not taken into account.

METHODS

The concept of a noninvasive surrogate of cardiac power output combines exercise systolic BP (SBP), as an estimate of afterload, with O(2)max, as an estimate of exercise cardiac output neglecting preload. Thus, a variable termed exercise cardiac power (ECP) is defined as the product of O(2)max (expressed as a percent predicted value) and SBP (ECP, expressed as %mm Hg, is the product of O(2)max, expressed as percentage of predicted maximum, times systolic pressure. The prognostic value of ECP obtained during routine treadmill ergospirometry was assessed in patients referred to our heart failure clinic. Patients undergoing heart transplantation were censored at the time of transplantation.

RESULTS

One hundred fifty-four patients were followed prospectively for a mean (+/- SE) duration of 625 +/- 32 days. Thirty-two patients (21%) died. ECP was the most powerful predictor of mortality, was the combined end point of mortality or hospitalization for worsening heart failure (all p < 0.001), and was an independent predictor in multivariate analysis. An ECP of < 5,000 %mm Hg indicated a poor prognosis with a 1-year mortality rate of 37%, whereas only 2% of the patients having an ECP of > 9,000 %mm Hg died during the first year.

CONCLUSION

The integration of afterload and O(2)max improves the prognostic value of each indicator, and provides an easily available and independent predictor of mortality and morbidity in CHF patients. This integrative concept of cardiac hydraulic performance is superior to O(2)max and can be used in routine ergospirometry.