The potential role of cardiac resynchronization therapy in acute heart failure syndromes

Cardiac Resynchronization Therapy in Cardiogenic Shock: A Case-Based Discussion

Cardiac resynchronization therapy (CRT) has consistently proven its capability to improve the left ventricular ejection fraction (LVEF). The benefits and indications for this therapy have been elucidated in current heart failure guidelines. However, it remains a topic of discussion if there is a role for it in acute heart failure syndromes (AHFSs). We present the case of a 55-year-old male with a medical history of alcohol-induced cardiomyopathy presenting with a new left bundle branch block, a widened QRS (154 ms), and cardiogenic shock (CS). After a lack of improvement with optimal medical management, CRT was used as a last resort. After implantation, the patient had a satisfactory clinical course and the LVEF improved. At the four-month follow-up, he underwent an outpatient transthoracic echocardiogram with further augmentation of his LVEF, improvement of his functional class, and no reported acute heart failure events. This case illustrates a potential therapeutic option for CS with a widened QRS. Prospective trials should include AHFSs to clarify the utility of CRT in this patient population.

Economic impact of heart failure according to the effects of kidney failure

INTRODUCTION AND OBJECTIVES

To evaluate the use of health care resources and their cost according to the effects of kidney failure in heart failure patients during 2-year follow-up in a population setting.

METHODS

Observational retrospective study based on a review of medical records. The study included patients ≥ 45 years treated for heart failure from 2008 to 2010. The patients were divided into 2 groups according to the presence/absence of KF. Main outcome variables were comorbidity, clinical status (functional class, etiology), metabolic syndrome, costs, and new cases of cardiovascular events and kidney failure. The cost model included direct and indirect health care costs. Statistical analysis included multiple regression models.

RESULTS

The study recruited 1600 patients (prevalence, 4.0%; mean age 72.4 years; women, 59.7%). Of these patients, 70.1% had hypertension, 47.1% had dyslipidemia, and 36.2% had diabetes mellitus. We analyzed 433 patients (27.1%) with kidney failure and 1167 (72.9%) without kidney failure. Patients with kidney failure were associated with functional class III-IV (54.1% vs 40.8%) and metabolic syndrome (65.3% vs 51.9%, P<.01). The average unit cost was €10,711.40. The corrected cost in the presence of kidney failure was €14,868.20 vs €9,364.50 (P=.001). During follow-up, 11.7% patients developed ischemic heart disease, 18.8% developed kidney failure, and 36.1% developed heart failure exacerbation.

CONCLUSIONS

Comorbidity associated with heart failure is high. The presence of kidney failure increases the use of health resources and leads to higher costs within the National Health System.

Efficacy of cardiac resynchronization in acutely infarcted canine hearts with electromechanical dyssynchrony

BACKGROUND

Patients with acute myocardial infarction (MI), left bundle branch block (LBBB), and marked left ventricular (LV) decompensation suffer from nearly 50% early mortality. Whether cardiac resynchronization therapy (CRT) improves hemodynamic status in this condition is unknown. We tested CRT in this setting by using a canine model of delayed lateral wall (LW) activation combined with 2 hours of coronary artery occlusion-reperfusion.

OBJECTIVE

This study aimed to evaluate the acute hemodynamic effects of CRT during and immediately after MI.

METHODS

Adult dogs (n = 8) underwent open-chest 2-hour mid-left anterior descending artery occlusion followed by 1-hour reperfusion. Four pacing modes were compared: right atrial pacing, pseudo-left bundle block (right ventricular pacing), and CRT with the LV lead positioned at either the LW (LW-CRT) or the peri-infarct zone (peri-infarct zone-CRT). Continuous LV pressure-volume data, regional segment length, and proximal left anterior descending flow rates were recorded.

RESULTS

At baseline, both right ventricular pacing and peri-infarct zone CRT reduced anterior wall regional work by ~50% (vs right atrial pacing). During coronary occlusion, this territory became dyskinetic, and dyskinesis rose further with both CRT modes as compared to pseudo-LBBB. Global cardiac output, stroke work, and ejection fraction all still improved by 11%-23%. After reperfusion, both CRT modes elevated infarct zone regional work and blood flow by ~10% as compared to pseudo-LBBB, as well as improved global function.

CONCLUSION

CRT improves global chamber systolic function in left ventricles with delayed LW activation during and after sustained coronary occlusion. It does so while modestly augmenting infarct zone dyskinesis during occlusion and improving regional function and blood flow after reperfusion. These findings support CRT in the setting of early post-MI dyssynchronous heart failure.

The global health and economic burden of hospitalizations for heart failure: lessons learned from hospitalized heart failure registries

Heart failure is a global pandemic affecting an estimated 26 million people worldwide and resulting in more than 1 million hospitalizations annually in both the United States and Europe. Although the outcomes for ambulatory HF patients with a reduced ejection fraction (EF) have improved with the discovery of multiple evidence-based drug and device therapies, hospitalized heart failure (HHF) patients continue to experience unacceptably high post-discharge mortality and readmission rates that have not changed in the last 2 decades. In addition, the proportion of HHF patients classified as having a preserved EF continues to grow and may overtake HF with a reduced EF in the near future. However, the prognosis for HF with a preserved EF is similar and there are currently no available disease-modifying therapies. HHF registries have significantly improved our understanding of this clinical entity and remain an important source of data shaping both public policy and research efforts. The authors review global HHF registries to describe the patient characteristics, management, outcomes and their predictors, quality improvement initiatives, regional differences, and limitations of the available data. Moreover, based on the lessons learned, they also propose a roadmap for the design and conduct of future HHF registries.

Clinical profile and prognostic value of low systolic blood pressure in patients hospitalized for heart failure with reduced ejection fraction: insights from the Efficacy of Vasopressin Antagonism in Heart Failure: Outcome Study with Tolvaptan (EVEREST) trial

BACKGROUND

Systolic blood pressure (SBP) is related to the pathophysiologic development and progression of heart failure (HF) and is inversely associated with adverse outcomes during hospitalization for HF (HHF). The prognostic value of SBP after initiating inhospital therapy and the mode of death and etiology of cardiovascular readmissions based on SBP have not been well characterized in HHF.

METHODS

A post hoc analysis was performed of the placebo group (n = 2061) of the EVEREST trial, which enrolled patients within 48 hours of admission for worsening HF with an ejection fraction (EF) ≤40% and an SBP ≥90 mm Hg, for a median follow-up of 9.9 months. Systolic blood pressure was measured at baseline, daily during hospitalization, and at discharge/day 7. Patients were divided into the following quartiles by SBP at baseline: ≤105, 106 to 119, 120 to 130, and ≥131 mm Hg. Outcomes were all-cause mortality (ACM) and the composite of cardiovascular mortality or HHF (CVM + HHF). The associations between baseline, discharge, and inhospital change in SBP and ACM and CVM + HHF were assessed using multivariable Cox proportional hazards regression models adjusted for known covariates.

RESULTS

Median (25th, 75th) SBP at baseline was 120 (105, 130) mm Hg and ranged from 82 to 202 mm Hg. Patients with a lower SBP were younger and more likely to be male; had a higher prevalence of prior revascularization and ventricular arrhythmias; had a lower EF, worse renal function, higher natriuretic peptide concentrations, and wider QRS durations; and were more likely to require intravenous inotropes during hospitalization. Lower SBP was associated with increased mortality, driven by HF and sudden cardiac death, and cardiovascular hospitalization, primarily caused by HHF. After adjusting for potential confounders, SBP was inversely associated with risk of the coprimary end points both at baseline (ACM: hazard ratio [HR]/10-mm Hg decrease 1.15, 95% CI1.08-1.22; CVM + HHF: HR 1.09/10-mm Hg decrease, 95% CI 1.04-1.14) and at the time of discharge/day 7 (ACM: HR 1.15/10-mm Hg decrease, 95% CI 1.08-1.22; CVM + HHF: HR 1.07/10-mm Hg decrease, 95% CI 1.02-1.13), but the association with inhospital SBP change was not significant.

CONCLUSION

Systolic blood pressure is an independent clinical predictor of morbidity and mortality after initial therapy during HHF with reduced EF.

Rehospitalization for heart failure: problems and perspectives

With a prevalence of 5.8 million in the United States alone, heart failure (HF) is associated with high morbidity, mortality, and healthcare expenditures. Close to 1 million hospitalizations for heart failure (HHF) occur annually, accounting for over 6.5 million hospital days and a substantial portion of the estimated $37.2 billion that is spent each year on HF in the United States. Although some progress has been made in reducing mortality in patients hospitalized with HF, rates of rehospitalization continue to rise, and approach 30% within 60 to 90 days of discharge. Approximately half of HHF patients have preserved or relatively preserved ejection fraction (EF). Their post-discharge event rate is similar to those with reduced EF. HF readmission is increasingly being used as a quality metric, a basis for hospital reimbursement, and an outcome measure in HF clinical trials. In order to effectively prevent HF readmissions and improve overall outcomes, it is important to have a complete and longitudinal characterization of HHF patients. This paper highlights management strategies that when properly implemented may help reduce HF rehospitalizations and include adopting a mechanistic approach to cardiac abnormalities, treating noncardiac comorbidities, increasing utilization of evidence-based therapies, and improving care transitions, monitoring, and disease management.