Left Bundle Branch Area Pacing versus Biventricular Pacing for Cardiac Resynchronization Therapy on Morbidity and Mortality

BACKGROUND

Left bundle branch area pacing (LBBAP) has emerged as an alternative to biventricular pacing (BVP) for cardiac resynchronization therapy (CRT). We aimed to compare the morbidity and mortality associated with LBBAP versus BVP in patients undergoing CRT implantation.

METHODS

Consecutive patients who received CRT from two high-volume implantation centers were retrospectively recruited. The primary endpoint was a composite of all-cause death and heart failure hospitalization, and the secondary endpoint was all-cause death.

RESULTS

A total of 491 patients receiving CRT (154 via LBBAP and 337 via BVP) were included, with a median follow-up of 31 months. The primary endpoint was reached by 21 (13.6%) patients in the LBBAP group, as compared with 74 (22.0%) patients in the BVP group [hazard ratio (HR) 0.70, 95% confidence interval (CI) 0.43-1.14, P = 0.15]. There were 10 (6.5%) deaths in the LBBAP group, as compared with 31 (9.2%) in the BVP group (HR 0.91, 95% CI 0.44-1.86, P = 0.79). No significant difference was observed in the risk of either the primary or secondary endpoint between LBBAP and BVP after multivariate Cox regression (HR 0.74, 95% CI 0.45-1.23, P = 0.24, and HR 0.77, 95% CI 0.36-1.67, P = 0.51, respectively) or propensity score matching (HR 0.72, 95% CI 0.41-1.29, P = 0.28, and HR 0.69, 95% CI 0.29-1.65, P = 0.40, respectively).

CONCLUSION

LBBAP was associated with a comparable effect on morbidity and mortality relative to BVP in patients with indications for CRT.

Prognostic value of the MELD-XI score in patients undergoing cardiac resynchronization therapy

Aims

Multi‐organ dysfunction was recently reported to be a common condition in patients with heart failure (HF). The Model for End‐stage Liver Disease eXcluding International normalized ratio (MELD‐XI) score reflects liver and kidney function. The prognostic relevance of this score has been reported in patients with a variety of cardiovascular diseases who are undergoing interventional therapies. However, the relationship between the severity of hepatorenal dysfunction assessed by the MELD‐XI score and the long‐term clinical outcomes of HF patients receiving cardiac resynchronization therapy (CRT) has not been evaluated.

Methods and results

Clinical records of 283 patients who underwent CRT implantation between March 2003 and October 2020 were retrospectively evaluated (mean age 67 ± 12, 22.6% female). Blood samples were collected before CRT implantation. Patients were divided into three groups based on tertiles of the MELD‐XI score: first tertile (MELD‐XI = 9.44, n = 95), second tertile (9.44 < MELD‐XI < 13.4, n = 94), and third tertile (MELD‐XI ≥ 13.4, n = 94). The primary endpoint was all‐cause mortality. Compared with the other groups, the third tertile group exhibited significantly older age, higher prevalence of diabetes mellitus and hypertension, lower haemoglobin level, and higher N‐terminal pro‐brain natriuretic peptide level (all P < 0.05). The functional CRT response rate was also significantly lower in the third tertile group (P = 0.011). During a median follow‐up of 30 months (inter‐quartile range, 9–67), 105 patients (37.1%) died. Kaplan–Meier analysis revealed that patients with a higher MELD‐XI score had a greater risk of all‐cause mortality (log‐rank test: P < 0.001). Even after adjustment for clinically relevant factors and a conventional risk score, the MELD‐XI score was still associated with mortality (adjusted hazard ratio: 1.04, 95% confidence interval: 1.00–1.07, P = 0.014, and adjusted hazard ratio: 1.04, 95% confidence interval: 1.01–1.09, P = 0.005, respectively). A higher MELD‐XI score was associated with a greater risk of all‐cause mortality than a lower MELD‐XI score regardless of whether a pacemaker or defibrillator was implanted (log‐rank test: P = 0.010 and P < 0.001, respectively).

Conclusions

Impaired hepatorenal function assessed by the MELD‐XI score was associated with older age, higher prevalence of multiple co‐morbidities, severity of HF, lower CRT response rates, and subsequent all‐cause mortality in HF patients undergoing CRT implantation. These results suggest that the MELD‐XI score can provide additional prognostic information and may be useful for improving risk stratification in this population.

Using ensemble of ensemble machine learning methods to predict outcomes of cardiac resynchronization

INTRODUCTION

The efficacy of cardiac resynchronization therapy (CRT) has been widely studied in the medical literature; however, about 30% of candidates fail to respond to this treatment strategy. Smart computational approaches based on clinical data can help expose hidden patterns useful for identifying CRT responders.

METHODS

We retrospectively analyzed the electronic health records of 1664 patients who underwent CRT procedures from January 1, 2002 to December 31, 2017. An ensemble of ensemble (EoE) machine learning (ML) system composed of a supervised and an unsupervised ML layers was developed to generate a prediction model for CRT response.

RESULTS

We compared the performance of EoE against traditional ML methods and the state-of-the-art convolutional neural network (CNN) model trained on raw electrocardiographic (ECG) waveforms. We observed that the models exhibited improvement in performance as more features were incrementally used for training. Using the most comprehensive set of predictors, the performance of the EoE model in terms of the area under the receiver operating characteristic curve and F1-score were 0.76 and 0.73, respectively. Direct application of the CNN model on the raw ECG waveforms did not generate promising results.

CONCLUSION

The proposed CRT risk calculator effectively discriminates which heart failure (HF) patient is likely to respond to CRT significantly better than using clinical guidelines and traditional ML methods, thus suggesting that the tool can enhanced care management of HF patients by helping to identify high-risk patients.

The CHA2DS2-VASc Score and Its Association with Long-Term Outcome in a Cardiac Resynchronization Therapy Population

BACKGROUND

Cardiac resynchronization therapy (CRT) is commonly used in patients with heart failure and left ventricular dyssynchrony. Several scoring systems have been tested in order to predict long-term outcome. Although intended for use in patients with atrial fibrillation, we sought to assess the performance of the CHA2DS2-VASc score in a CRT population.

METHODS

Data on 796 consecutive CRT patients were retrospectively gathered from hospital records and healthcare registries. CHA2DS2-VASc scores were calculated, as well as other stratification scores for comparison. The outcomes were crude mortality, time to first heart failure hospitalization, and a composite of the 2. CHA2DS2-VASc score was evaluated against the end points with survival analyses and compared to other risk stratification scores.

RESULTS

The CHA2DS2-VASc score was significantly correlated with both outcomes in univariable and multivariable analysis adjusting for other known predictors of CRT outcome (unadjusted HR 1.28, 95% CI 1.21-1.36 and HR 1.19, 95% CI 1.13-1.25 for the mortality and heart failure hospitalization end points, respectively). Its performance compared well to other validated scores for the mortality end point (Harrell's C: 0.61, range for other scoring systems: 0.57-0.65), as well as the heart failure hospitalization end point (Harrell's C: 0.57, range of other scoring systems: 0.58-0.62). It correlated to 5- and 10-year survival with an area under the curve of 0.63 and 0.73, respectively.

CONCLUSION

When tested for association with outcome in a CRT population, the CHA2DS2-VASc score correlates to increased mortality and risk of heart failure hospitalization. It performs similarly to CRT-specific scores. However, the results of this study indicate that all tested scores should be used with caution in CRT patients.

Application of the heart failure meta-score to predict prognosis in patients with cardiac resynchronization defibrillators

BACKGROUND

The Heart Failure (HF) Meta-score may be useful in predicting prognosis in patients with primary prevention cardiac resynchronization defibrillators (CRT-D) considering the competing risk of appropriate defibrillator shock versus mortality.

METHODS

Data from 648 consecutive patients from two centers were used for the evaluation of the performance of the HF Meta-score. The primary endpoint was mortality and the secondary endpoint was time to first appropriate implantable cardioverter-defibrillator (ICD) shock or death without prior appropriate ICD shock. Fine-Gray model was used for competing risk regression analysis.

RESULTS

In the entire cohort, 237 patients died over a median follow-up of 5.2 years. Five-year cumulative incidence of mortality ranged from 12% to 53%, for quintiles 1 through 5 of the HF Meta-score, respectively (log-rank P < 0.001). Compared with the lowest quintile, mortality risk was higher in the highest quintile (HR 6.9; 95%CI 3.7-12.8). The HF Meta-score had excellent calibration, accuracy, and good discrimination in predicting mortality (C-statistic 0.76 at 1-year and 0.71 at 5-year). The risk of death without appropriate ICD shock was higher in risk quintile 5 compared to quintile 1 (sub HR 5.8; 95%CI 3.1-11.0, P < 0.001).

CONCLUSIONS

Our study demonstrated a good ability of the HF Meta-score to predict survival in HF patients treated with CRT-D as primary prevention. The HF Meta-score proved to be useful in identifying a subgroup with a significantly poor prognosis despite a CRT-D.

The VALID-CRT risk score reliably predicts response and outcome of cardiac resynchronization therapy in a real-world population

OBJECTIVES

The aim of the study was to confirm the value of the VALID-cardiac resynchronization therapy (CRT) risk score in predicting outcome and to assess its association with clinical response (CR) in an unselected real-world CRT population.

METHODS AND RESULTS

The present analysis comprised all consecutive CRT patients (pts) enrolled in the CRT-MORE registry from 2011 to 2013. Pts were stratified into five groups (quintiles 1-5) according to the VALID-CRT risk predictor index applied to the CRT-MORE population. In the analysis of clinical outcome, adverse events comprised death from any cause and non-fatal heart failure (HF) events requiring hospitalization. CR at 12-month follow-up was also assessed. We enrolled 905 pts. During a median follow-up of 1005 [627-1361] days, 134 patients died, and 79 had at least one HF hospitalization. At 12 months, 69% of pts displayed an improvement in their CR. The mean VALID-CRT risk score derived from the CRT-MOdular Registry (MORE) population was 0.317, ranging from -0.419 in Q1 to 2.59 in Q5. The risk-stratification algorithm was able to predict total mortality after CRT (survival ranging from 93%-Q1 to 77%-Q5; hazards ratio [HR] = 1.42, 95% confidence interval [CI]: 1.25-1.61, P < .0001), and HF hospitalization (ranging from 95% to 90%; HR = 1.24, 95% CI: 1.06-1.45, P = .009). CR was significantly lower in pts with a high-to-very high risk profile (Q4-5) than in pts with a low-to-intermediate risk profile (Q1-2-3) (55% vs 79%, P < .0001).

CONCLUSION

The VALID-CRT risk-stratification algorithm reliably predicts outcome and CRT response after CRT in an unselected, real-world population.

An Appraisal of Biomarker-Based Risk-Scoring Models in Chronic Heart Failure: Which One Is Best?

PURPOSE OF REVIEW

While prediction models incorporating biomarkers are used in heart failure, these have shown wide-ranging discrimination and calibration. This review will discuss externally validated biomarker-based risk models in chronic heart failure patients assessing their quality and relevance to clinical practice.

RECENT FINDINGS

Biomarkers may help in determining prognosis in chronic heart failure patients as they reflect early pathologic processes, even before symptoms or worsening disease. We present the characteristics and describe the performance of 10 externally validated prediction models including at least one biomarker among their predictive factors. Very few models report adequate discrimination and calibration. Some studies evaluated the additional predictive value of adding a biomarker to a model. However, these have not been routinely assessed in subsequent validation studies. New and existing prediction models should include biomarkers, which improve model performance. Ongoing research is needed to assess the performance of models in contemporary patients.

Predictors of long-term mortality with cardiac resynchronization therapy in mild heart failure patients with left bundle branch block

BACKGROUND

Cardiac resynchronization therapy (CRT) is highly beneficial in patients with heart failure (HF) and left bundle branch block (LBBB); however, up to 30% of patients in this selected group are nonresponders.

HYPOTHESIS

We hypothesized that clinical and echocardiographic variables can be used to develop a simple mortality risk stratification score in CRT.

METHODS

Best-subsets proportional-hazards regression analysis was used to develop a simple clinical risk score for all-cause mortality in 756 patients with LBBB allocated to the CRT with defibrillator (CRT-D) group enrolled in the multicenter automatic defibrillator implantation trial with cardiac resynchronization therapy. The score was used to assess the mortality risk within the CRT-D group and the associations with mortality reduction with CRT-D vs implantable cardioverter defibrillator (ICD) in each risk category.

RESULTS

Four clinical variables comprised the risk score: age ≥ 65, creatinine ≥ 1.4 mg/dL, history of coronary artery bypass graft, and left ventricular ejection fraction (LVEF) < 26%. Every 1 point increase in the score was associated with 2-fold increased mortality within the CRT-D arm (P < 0.001). CRT-D was associated with mortality reduction as compared with ICD only in patients with moderate risk: score 0 (HR = 0.80, P = 0.615), score 1 (HR = 0.54, P = 0.019), score 2 (HR = 0.54, P = 0.016), score 3-4 risk factors (HR = 1.08, P = 0.811); however, the device by score interaction was not significant (P = 0.306). The score was also significantly predictive of left ventricular reverse remodeling (P < 0.001).

CONCLUSIONS

Four clinical variables can be used for improved mortality risk stratification in mild HF patients with LBBB implanted with CRT-D.

Association between quality of life and prognosis of candidate patients for heart transplantation: a cross-sectional study

OBJECTIVE

to verify the association between the prognostic scores and the quality of life of candidates for heart transplantation.

METHOD

a descriptive cross-sectional study with a convenience sample of 32 outpatients applying to heart transplantation. The prognosis was rated by the Heart Failure Survival Score (HFSS) and the Seattle Heart Failure Model (SHFM); and the quality of life by the Minnesota Living With Heart Failure Questionnaire (MLHFQ) and the Kansas City Cardiomyopathy Questionnaire (KCCQ). The Pearson correlation test was applied.

RESULTS

the correlations found between general quality of life scores and prognostic scores were (HFSS/MLHFQ r = 0.21), (SHFM/MLHFQ r = 0.09), (HFSS/KCCQ r = -0.02), (SHFM/KCCQ r = -0.20).

CONCLUSION

the weak correlation between the prognostic and quality of life scores suggests a lack of association between the measures, i.e., worse prognosis does not mean worse quality of life and the same statement is true in the opposite direction.

Palliative Care in Heart Failure

PURPOSE OF REVIEW

This review illustrates the dynamic role of palliative care in heart failure management and encapsulates the commonly utilized pharmacologic and non-pharmacologic therapeutic strategies for symptom palliation in heart failure. In addition, we provide our experience regarding patient care issues common to the domain of heart failure and palliative medicine which are commonly encountered by heart failure teams.

RECENT FINDINGS

Addition of palliative care to conventional heart failure management plan results in improvement in quality of life, anxiety, depression, and spiritual well-being among patients. Palliative care should not be confused with hospice care. Palliative care teams should be involved early in the care of heart failure patients with the aims of improving symptom palliation, discussing goals of care and improving quality of life without compromising utilization of evidence-based heart failure therapies. A consensus on the appropriate timing of involvement and evidence for many symptom palliation therapies is still emerging.

Usefulness of the CRT-SCORE for Shared Decision Making in Cardiac Resynchronization Therapy in Patients With a Left Ventricular Ejection Fraction of ≤35

Individualized estimation of prognosis after cardiac resynchronization therapy (CRT) remains challenging. Our aim was to develop a multiparametric prognostic risk score (CRT-SCORE) that could be used for patient-specific clinical shared decision making about CRT implantation. The CRT-SCORE was derived from an ongoing CRT registry, including 1,053 consecutive patients (age 67 ± 10 years, 76% male). Using preimplantation variables, 100 multiple imputed datasets were generated for model calibration. Based on multivariate Cox regression models, cross-validated linear prognostic scores were calculated, as well as survival fractions at 1 and 5 years. Specifically, the CRT-SCORE was calculated using atrioventricular junction ablation, age, gender, etiology, New York Heart Association class, diabetes, hemoglobin level, renal function, left bundle branch block, QRS duration, atrial fibrillation, left ventricular systolic and diastolic functions, and mitral regurgitation, and showed a good discriminative ability (areas under the curve 0.773 at 1 year and 0.748 at 5 years). During the long-term follow-up (median 60 months, interquartile range 31 to 85), all-cause mortality was observed in 494 (47%) patients. Based on the distribution of the CRT-SCORE, lower- and higher-risk patient groups were identified. Estimated mean survival rates of 98% at 1 year and 92% at 5 years were observed in the lowest 5% risk group (L5 CRT-SCORE: -4.42 to -1.60), whereas the highest 5% risk group (H5 CRT-SCORE: 1.44 to 2.89) showed poor survival rates: 78% at 1 year and 22% at 5 years. In conclusion, the CRT-SCORE allows accurate prediction of 1- and 5-year survival rates after CRT using readily available and CRT-specific clinical, electrocardiographic, and echocardiographic parameters. The model may assist clinicians in counseling patients and in decision making.

Clinical risk profile score predicts all cause mortality but not implantable cardioverter defibrillator intervention rate in a large unselected cohort of patients with congestive heart failure

BACKGROUND

Primary prophylactic implantable cardioverter defibrillator (ICD) therapy is indicated for patients with reduced left ventricular ejection fraction (LVEF). We aimed to determine if preoperative clinical risk profiling can predict long-term benefit, and if clinical risk scores can be applied and improved in a patient cohort outside the clinical trial setting.

METHODS

Using registry data, 789 patients with reduced LVEF who received ICDs for primary prevention during 2006-2011 were identified (age 64 ± 11 years, 82% men, 63% ischemic etiology, 52% cardiac resynchronization therapy with defibrillator). The patients were divided into three risk groups, based on the presence of baseline clinical risk factors (age >70, QRS duration >120 ms, New York Heart Association class III-IV, atrial fibrillation history, or creatinine >106 μmol/L). Endpoints were all-cause mortality and survival free of adequate ICD therapy.

RESULTS

Mean follow-up was 39 ± 18 months. Annual mortality was 7.6%, and increased with risk group (p < .001). Rates of appropriate antitachycardia pacing and shock therapy were not statistically different between the groups, and ranged from 11%-16% and 6%-14%, respectively. By combining the previous risk score with data on diabetes, a better independent prediction of mortality was achieved; mortality rates then ranged from 11% (low-risk) to 46% (high-risk) (p < .0001).

CONCLUSIONS

Implantable cardioverter defibrillator therapies occur across the spectrum of comorbidities in a population with systolic heart failure. However, all-cause mortality is considerably higher in the group of patients with accumulated risk factors, and using the proposed scoring system can be helpful for the evaluation and risk stratification of the patient prior to making a decision for a primary prophylactic ICD implantation.

Is cardiopulmonary exercise testing essential to indicate ventricular assist device implantation in patients with INTERMACS profile 4-7?

Cardiopulmonary exercise testing (CPXT) is a promising tool for predicting 2-year cardiac death or ventricular assist device (VAD) implantation in patients assigned to INTERMACS profile 4-7. However, CPXT is not available in all hospitals. We evaluated 130 patients <65 years old with advanced heart failure assigned to INTERMACS profile 4-7 who underwent CPXT. CPXT scores (0-8 points), which we created recently, and the Seattle HF Model (SHFM) scores were both significant predictors of 2-year cardiac death or VAD implantation (14 events) by Cox-regression analysis (P < 0.05 for both) and had comparable areas under the curve (AUCs) in receiver operating characteristic analyses (0.811 vs. 0.737, P > 0.05). The combination score: age <46 years and serum sodium concentration <137 mEq/L, both of which were significant predictors of cardiac death or VAD implantation by uni/multivariate Cox-regression analyses, had a significantly higher AUC than did CPXT scores (0.909, P < 0.05). In a validation study, the AUC of the combination score was comparable with that of SHFM among 52 patients <65 years old receiving adaptive servo-ventilator treatment (0.753 vs. 0.794, P > 0.05). In conclusion, VAD indication may be discussed without CPXT in patients <65 years old with INTERMACS profile 4-7 at least in the current Japanese situation.

Outcome of conservative management vs. assist device implantation in patients with advanced refractory heart failure

BACKGROUND

In patients with advanced refractory heart failure (HF) cardiac transplantation (HTX), conservative medical management and the implantation of a ventricular assist device (VAD) represent valuable options. The determination of the best therapeutic destination strategy for the individual patient remains a challenge. The aim of this study was to assess the clinical outcome in advanced refractory HF patients either managed conservatively receiving optimal contemporary medical therapy ('conservative'), or who who underwent pulsatile flow VAD ('pVAD') or continuous-flow VAD ('contVAD') implantation.

MATERIALS AND METHODS

A total of 118 patients with INTERMACS profile >1 at baseline, who died, or fully completed a 24-month follow-up free from HTX were included into this retrospective analysis. All-cause mortality at 24 months was assessed and compared between the three groups.

RESULTS

Fifty (42%) patients were managed conservatively, 25 (21%) received a pVAD and 43 (36%) a contVAD. NT-proBNP values were comparable between the three groups (median 4402 (IQR 2730-13390) pg/mL, 3580 (1602-6312) pg/mL and 3693 (2679-8065) pg/mL, P = 0·256). Mean survival was 18·6 (95% CI 16·2-21·0) months for patients managed conservatively, 7·0 (3·9-10·0) for pVAD and 20·5 (18·2-22·8) for contVAD (overall log-rank test P < 0·001). Conservatively managed patients spent a mean of 22·4 (95% CI 22·1-22·8), pVAD 17·7 (15·4-20·1) and contVAD 21·6 (21·2-22·1) months out of hospital (conservative vs. pVAD P < 0·001; conservative vs. contVAD P = 0·015; pVAD vs. contVAD P < 0·001).

CONCLUSIONS

In accordance with the literature, contVAD resulted in a significantly better clinical outcome than pVAD implantation. However, conservative management with current optimal medical therapy appears to remain a valuable option for patients with advanced HF.

Predictors of mortality, LVAD implant, or heart transplant in primary prevention cardiac resynchronization therapy recipients: The HF-CRT score

BACKGROUND

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality among individuals with dyssynchronous systolic heart failure (HF). However, patient outcomes vary, with some at higher risk than others for HF progression and death.

OBJECTIVE

To develop a risk prediction score incorporating variables associated with mortality, left ventricular assist device (LVAD) implant, or heart transplant in recipients of a primary prevention cardiac resynchronization therapy-defibrillator (CRT-D).

METHODS

We followed 305 CRT-D patients from the Prospective Observational Study of Implantable Cardioverter-Defibrillators for the composite outcome of all-cause mortality, LVAD implant, or heart transplant soon after device implantation. Serum biomarkers and electrocardiographic and clinical variables were collected at implant. Multivariable analysis using the Cox proportional hazards model with stepwise selection method was used to fit the final model.

RESULTS

Among 305 patients, 53 experienced the composite endpoint. In multivariable analysis, 5 independent predictors ("HF-CRT") were identified: high-sensitivity C-reactive protein >9.42 ng/L (HR = 2.5 [1.4, 4.5]), New York Heart Association functional class III/IV (HR = 2.3 [1.2, 4.5]), creatinine >1.2 mg/dL (HR = 2.7 [1.4, 5.1]), red blood cell count <4.3 × 10(6)/μL (HR = 2.4 [1.3, 4.7]), and cardiac troponin T >28 ng/L (HR = 2.7 [1.4, 5.2]). One point was attributed to each predictor and 3 score categories were identified. Patients with scores 0-1, 2-3, and 4-5 had a 3-year cumulative event-free survival of 96.8%, 79.7%, and 35.2%, respectively (log-rank, P < .001).

CONCLUSION

A simple score combining clinical and readily available biomarker data can risk-stratify CRT patients for HF progression and death. These findings may help identify patients who are in need of closer monitoring or early application of more aggressive circulatory support.

Validation of a simple risk stratification tool for patients implanted with Cardiac Resynchronization Therapy: the VALID-CRT risk score

AIMS

Mortality after cardiac resynchronization therapy (CRT) is difficult to predict. We sought to design and validate a simple prognostic score for patients implanted with CRT, based on readily available clinical variables, including age, gender, left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) class, presence/absence of atrial fibrillation, presence/absence of atrioventricular junction ablation, coronary heart disease, diabetes, and implantation of a CRT device with defibrillation.

METHODS

For predictive modelling, 5153 consecutive patients enrolled in 72 European centres (79% male; LVEF 25.9 ± 6.85%; NYHA class III-IV 77.5%; QRS 158.4 ± 32.3 ms) were randomly split into derivation (70%) and validation (30%) samples. The primary endpoint was total mortality and the secondary endpoint was cardiovascular mortality. The final predictive model fit was assessed by plotting observed vs. predicted survival.

RESULTS

In the entire cohort, 1004 deaths occurred over a follow-up of 14 409 person years. Total mortality ranged from 3.1% to 28.2% at 2 years in the first and fifth quintile of the risk score, respectively. At 5 years, total mortality was 10.3%, 18.6%, 27.6%, 36.1%, and 58.8%, from the first to the fifth quintile. Compared with the lowest quintile (Q), total mortality was significantly higher in the other four quintiles [Q2 hazard ratio (HR) = 1.71; Q3 HR = 2.20; Q4 HR = 4.03; Q5 HR = 8.03; all P < 0.001). The final model, which was based on the entire cohort using the above variables, showed a good discrimination (Harrell's c = 0.70) and high explained variation (0.26). The mean predicted survival fitted well with the observed survival for up to 6 years of follow-up.

CONCLUSIONS

The VALID-CRT risk score, which is based on routine, readily available clinical variables, reliably predicted the long-term total and cardiovascular mortality in patients undergoing CRT. While this score cannot be used to predict the benefit of CRT, it may be useful for predicting survival after CRT. This may have useful implications for follow-up.

Prognostic scores in heart failure - Critical appraisal and practical use

Survival in patients with heart failure in the last two decades has significantly improved, owing to availability of new drugs, devices, and technologies. However, these new therapeutic tools are often costly and not without attendant risks. Thus, accurate and reproducible risk stratification is required to assess appropriateness of therapy. Although a growing body of evidence has characterized various predictors of poor outcomes, the application of comprehensive prognostic models in clinical practice remains limited. Herein, we critically evaluate the utility of prognostic scores in heart failure, discussing the strategies to select the most efficient and appropriate risk estimator in the individual patient.

Patient selection for advanced heart failure therapy referral

Despite advances in medical therapy for chronic heart failure (HF), advanced HF carries a dismal prognosis. Options such as transplantation and durable mechanical circulatory support have greatly improved outcomes for these patients, but their introduction has introduced significant complexity to patient management. Although much of this management occurs at specialized heart transplant centers, it is the responsibility of the primary cardiologist of the patient with advanced HF to refer patients at the appropriate time and to help them navigate the difficult decisions related to the pursuit of advanced therapies. We present a unique pathway that incorporates guidelines, recent data, and expert opinion to help general cardiologists determine which patients should be referred for transplantation or durable mechanical circulatory support, and when they should be referred. Decision making on referral to the heart transplant center is also summarized.

Utility of the Seattle Heart Failure Model in patients with cardiac resynchronization therapy and implantable cardioverter defibrillator referred for heart transplantation

BACKGROUND

The Seattle Heart Failure Model (SHFM) predicts survival in heart failure but may underestimate risk in severe heart failure, and the performance has not been evaluated explicitly in patients with cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillator (ICD) referred for heart transplantation. We aimed to assess the utility of the SHFM by validation in patients with CRT and/or ICD referred for heart transplantation.

METHODS

We assessed the SHFM performance in 382 patients with CRT and/or ICD referred for heart transplantation. Outcome was survival free from urgent transplantation or left ventricular assist device. Model discrimination and calibration were assessed graphically and by formal tests.

RESULTS

During a mean follow-up of 2.3 years, 195 events occurred. One-, 2-, and 3-year observed event-free survival was 77%, 62%, and 52%, and the observed to predicted event-free survival ratio was 0.89, 0.80, and 0.76. Calibration plots demonstrated results deviating from the ideal calibration line at 1, 2, and 3 years. The SHFM score adequately assigned patients in discrete risk strata, according to Kaplan-Meier estimated survival. Time-dependent receiver operating characteristic curve analyses demonstrated good discrimination overall, which was slightly better for 1-year (area under the curve [AUC] 0.774) compared with 2-year (AUC 0.742) and 3-year (AUC 0.728) event-free survival.

CONCLUSIONS

The SHFM has good discrimination but underestimates risk of adverse outcomes in patients with CRT and/or ICD referred for heart transplantation. The SHFM may be used to assess relative risk and changes over time, but when assessing absolute percentage of event-free survival, the overestimation of event-free survival should be accounted for.

EAARN score, a predictive score for mortality in patients receiving cardiac resynchronization therapy based on pre-implantation risk factors

AIMS

The beneficial effects of CRT in patients with advanced heart failure, wide QRS, and low LVEF have been clearly established. Nevertheless, mortality remains high in some patients. The aims of our study were to identify the predictors of mortality in patients treated with CRT and to design a risk score for mortality.

METHODS AND RESULTS

A cohort of 608 consecutive patients treated with CRT from 2000 to 2011 in our centre was prospectively analysed. Baseline clinical and echocardiography variables were analysed and mortality data were collected. During a mean follow-up of 36.2 ± 29.2 months, 174 patients died: 123/174 (71%) due to cardiovascular causes, 25/174 (14%) non-cardiac causes, and 26/174 (15%) unknown aetiology. In a multivariate analysis the predictors of mortality were NYHA class IV [hazard ratio (HR) 2.54, 95% confidence interval (CI) 1.7-3.7, P < 0.001], glomerular filtration rate (GFR) <60 mL/min/1.73 m2 (HR 1.61, 95% CI 1.14-2.30, P = 0.008), AF (HR 1.67, 95% CI 1.19-2.3, P = 0.01), age ≥70 years (HR 1.44, (95% CI 1.04-2.00, P = 0.02), and LVEF <22% (HR 1.83, 95% CI 1.33-2.52, P ≤ 0.001). The EAARN score (EF, Age, AF, Renal dysfunction, NYHA class IV) summarizes the predictors. Each additional predictor increased the mortality: one predictor, HR 3.28 (95% CI 1.37-7.8, P = 0.008); two, HR 5.23 (95% CI 2.24-12.10, P < 0.001); three, HR 9.63 (95% CI 4.1-22.60, P < 0.001); and four or more, HR 14.38 (95% CI 5.8-35.65, P < 0.001).

CONCLUSION

The predictors of mortality have a significant add-on predictive effect on mortality. The EAARN score could be useful to stratify the prognosis of CRT patients.

Predictors of mortality in patients with an implantable cardiac defibrillator: a systematic review and meta-analysis

BACKGROUND

Many current predictors of mortality in heart failure (HF) were evaluated before the use of implantable cardioverter defibrillators (ICDs). We conducted a meta-analysis to identify factors associated with mortality in ICD-HF patients.

METHODS

We searched in MedLine, EMBASE, and CINAHL in May 2012. Two reviewers selected citations that included ambulatory ICD patients and addressed the association between any predictor and mortality using multivariable regression. We meta-analyzed mortality using random-effects models.

RESULTS

Of 10,420 studies reviewed, 72 studies evaluating 63 predictors on 257,692 ICD patients proved eligible. High confidence in estimates was found for age (hazard ratio [HR], 1.45 for 10-year increase; 95% confidence interval [CI], 1.35-1.56), baseline glomerular filtration rate (HR, 1.25 for 15-mL/min decrease; 95% CI, 1.15-1.35), chronic obstructive pulmonary disease (HR, 1.54; 95% CI, 1.38-1.71), diabetes (HR, 1.56; 95% CI, 1.37-1.79), peripheral vascular disease (HR, 1.43; 95% CI, 1.2-1.72), left ventricular ejection fraction (HR, 0.77 for 10% increase; 95% CI, 0.73-0.83), and appropriate or inappropriate ICD shocks (HR, 2.34; 95% CI 1.59-3.44) New York Heart Association class, atrial fibrillation, and congestive HF were strongly associated with mortality but the confidence in estimates was low. Ischemic cardiomyopathy and male sex were not independent predictors of mortality.

CONCLUSIONS

This meta-analysis identified strong reliable mortality predictors in ICD-HF patients. Age, renal dysfunction, chronic obstructive pulmonary disease, diabetes, peripheral vascular disease, decreased left ventricular ejection fraction, and ICD shocks during follow-up were strong predictors of mortality; ischemic cardiomyopathy and male sex were not. Further research is needed to study other potential predictors, particularly biomarkers.