Revascularization for ischaemic cardiomyopathy:

New developments in the surgical management of end-stage heart failure

Heart failure is a major healthcare problem associated with morbidity and mortality. Despite progress in treatments, the prognosis of heart failure remains poor. Standard treatments for heart failure include medical therapy, resynchronization therapy, and cardiac surgery. Heart failure teams providing guideline based care assist in the optimal management for advanced heart failure. Progression of heart failure despite optimal management may be treated with heart transplant. In non-transplant eligible patients, implantable left ventricular assist devices (LVADs) may improve patients 'quality of life and survival. Advances in LVADs, including smaller size, increased device durability, and (near) totally implantable devices, may enable LVADs to become an option in less sick patients. Evolving therapeutics such as stem cells and novel therapeutics may be combined with LVADs to allow myocardial recovery. This article will review current and developing strategies in the surgical management of heart failure with an emphasis on LVAD therapy.

Isolated coronary artery bypass graft combined with bone marrow mononuclear cells delivered through a graft vessel for patients with previous myocardial infarction and chronic heart failure: a single-center, randomized, double-blind, placebo-controlled clinical trial

OBJECTIVES

This study aimed at examining the efficacy of bone marrow mononuclear cell (BMMNC) delivery through graft vessel for patients with a previous myocardial infarction (MI) and chronic heart failure during coronary artery bypass graft (CABG).

BACKGROUND

Little evidence exists supporting the practice of BMMNC delivery through graft vessel for patients with a previous MI and chronic heart failure during CABG.

METHODS

From November 2006 to June 2009, a randomized, placebo-controlled trial was conducted to test the efficacy and safety of CABG for multivessel coronary artery disease combined with autologous BMMNCs in patients with congestive heart failure due to severe ischemic cardiomyopathy. Sixty-five patients were recruited, and 60 patients remained in the final trial and were randomized to a CABG + BMMNC group (n = 31) and a placebo-control group (i.e., CABG-only group, n = 29). All patients discharged received a 6-month follow-up. Changes in left ventricular ejection fraction from baseline to 6-month follow-up, as examined by magnetic resonance imaging, were of primary interest.

RESULTS

The overall baseline age was 59.5 ± 9.2 years, and 6.7% were women. After a 6-month follow-up, compared with the placebo-control group, the CABG + BMMNC group had significant changes in left ventricular ejection fraction (p = 0.029), left ventricular end-systolic volume index (p = 0.017), and wall motion index score (p = 0.011). Also, the changes in the distance on the 6-min walking test as well as B-type natriuretic peptide were significantly greater in the CABG + BMMNC group than in the control group.

CONCLUSIONS

In summary, patients with a previous MI and chronic heart failure could potentially benefit from isolated CABG (i.e., those who received CABG only) combined with BMMNCs delivered through a graft vessel. (Stem Cell Therapy to Improve Myocardial Function in Patients Undergoing Coronary Artery Bypass Grafting [CABG]; NCT00395811).

Treatment of heart failure with normal ejection fraction

Heart failure (HF) is a major cause of mortality and morbidity and one of the most frequent reasons for hospital admission in the United States and Europe. Currently, more than 50% of HF patients have a normal (N) left ventricular (LV) ejection fraction (EF) (LVEF >50%). The main pathophysiologic processes involved in HFNEF are increased LV stiffness and abnormal relaxation, resulting in impaired LV filling. Hypertension and myocardial ischemia are the most common causes of HFNEF. Precipitating factors include volume overload, tachycardia, physical exercise, systemic stressors (such as fever and infection), arrhythmia, increased salt intake, and use of nonsteroidal anti-inflammatory drugs. There is little evidence to guide treatment, as previously HFNEF patients have been excluded from clinical trials on the basis of a normal LVEF. Survival improved over time in patients with reduced (R) EF (HFREF) (LVEF <40%), reflecting the beneficial effects of treatment in this phenotype. However, survival did not improve for HFNEF patients. The approach to the treatment of HFNEF patients should focus on reducing LV filling pressure, controlling hypertension, modifying ischemia, and improving LV relaxation. Therefore, diuretics are suitable for HFNEF patients to reduce ventricular filling pressure. Hypertension can be treated by using multiple agents if necessary. Drugs of particular interest and recommended to treat hypertension are calcium channel blockers (CCBs) and antagonists of the renin-angiotensin-aldosterone system, such as angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and aldosterone antagonists. Ischemic heart disease can be treated with antiplatelet therapy, anticoagulants, and β-blockers. Heart rate control in atrial fibrillation can be achieved with β-blockers and digoxin. Finally, ACE inhibitors and ARBs could potentially decrease LV hypertrophy in hypertensive patients with HFNEF.

Stem cell therapy for chronic myocardial infarction

Although recent advances for the treatment of myocardial infarction have dramatically increased the rate of survival after the ischemic event, this has also led to a rise in the number of chronic patients, making the finding of a suitable therapy a compulsory subject for modern medicine. Over the last decade, stem cells have been a promise for the cure of several diseases not only due to their plasticity but also to their capacity to act in a paracrine manner and influence the affected tissue, prompting the launching of several clinical trials. In spite of the knowledge already acquired, stem cell application to chronically infarcted hearts has been much less approached than its acute counterpart. Through this review, we will focus in stem cell therapy in animal models of chronic myocardial infarction: cell types employed, functional results, mechanisms analyzed, and questions raised.

Incident coronary revascularization and subsequent mortality in chronic heart failure: a propensity-matched study

INTRODUCTION

Ischemic heart disease (IHD) is common in heart failure (HF), yet the association between incident coronary revascularization and mortality in these patients has not been examined in a propensity-matched study.

METHODS

In the Digitalis Investigation Group trial, 2853 patients without coronary revascularization and 120 patients with coronary revascularization during the first three years were alive at the end of three years. We used propensity scores to match 119 and 357 patients with and without coronary revascularization. Matched Cox regression models were used to estimate hazard ratio (HR) and 95% confidence interval (CI) for mortality during the fourth year of follow-up, for all patients and by the mean left ventricular ejection fraction (LVEF) of 35%.

RESULTS

Coronary revascularization was associated with higher mean LVEF (36% versus 32%; p<0.0001) and prevalence of angina pectoris (48% versus 32%; p<0.0001) but fewer prior myocardial infarction (80% versus 87%; p=0.023), all of which were balanced post-match. All-cause mortality occurred in 5.9% and 6.2% patients respectively with and without coronary revascularization (HR for coronary revascularization, 0.95; 95% CI, 0.39-2.32; p=0.910). HR for mortality associated with coronary revascularization for patients with LVEF < or = 35% and >35% were respectively 1.34 (95% CI, 0.48-3.71; p=0.578) and 0.61 (95% CI, 0.13-2.87; p=0.532).

CONCLUSION

Chronic HF patients with IHD receiving coronary revascularization were more likely to have angina and higher LVEF. However, in a balanced propensity-matched cohort, there was no association between coronary revascularization and mortality. The LVEF-associated variation in mortality needs to be prospectively studied.