The year in heart failure

Pharmacological targeting of CDK9 in cardiac hypertrophy

Cardiac hypertrophy allows the heart to adapt to workload, but persistent or unphysiological stimulus can result in pump failure. Cardiac hypertrophy is characterized by an increase in the size of differentiated cardiac myocytes. At the molecular level, growth of cells is linked to intensive transcription and translation. Several cyclin-dependent kinases (CDKs) have been identified as principal regulators of transcription, and among these CDK9 is directly associated with cardiac hypertrophy. CDK9 phosphorylates the C-terminal domain of RNA polymerase II and thus stimulates the elongation phase of transcription. Chronic activation of CDK9 causes not only cardiac myocyte enlargement but also confers predisposition to heart failure. Due to the long interest of molecular oncologists and medicinal chemists in CDKs as potential targets of anticancer drugs, a portfolio of small-molecule inhibitors of CDK9 is available. Recent determination of CDK9's crystal structure now allows the development of selective inhibitors and their further optimization in terms of biochemical potency and selectivity. CDK9 may therefore constitute a novel target for drugs against cardiac hypertrophy.

Predictive value of high sensitivity CRP in patients with diastolic heart failure

BACKGROUND

C-reactive protein (CRP) has been tested in patients with systolic heart failure (HF) and mixed results have been obtained with regards to its potential predictive value. However, the role of C-reactive protein (CRP) in patients with diastolic HF is not established. We studied the predictive role of high sensitivity CRP (hsCRP) in patients with diastolic HF.

METHODS

HsCRP levels were measured in a cohort of CHF outpatients, 77 patients with diastolic HF and 217 patients with systolic HF. Concentrations were compared to a large cohort of healthy population (n=7701) and associated with the HF admissions and mortality of the patients.

RESULTS

Levels of hsCRP did not differ between patients with systolic and diastolic HF and were significantly elevated compared to the cohort of healthy subjects even after adjustment to various clinical parameters (p<0.0001). In patients with diastolic HF, hsCRP levels associated with New York Heart Association functional class (NYHA-FC) (r=0.31 p=0.01). On univariate Cox regression model hsCRP levels independently predicted hospitalizations in patients with systolic but not diastolic HF (p=0.047).

CONCLUSION

HsCRP concentrations are elevated in patients with diastolic HF and correlate with disease severity; their prognostic value in this patient population should be further investigated.

Circulating endothelial progenitor cells and clinical outcome in patients with congestive heart failure

BACKGROUND

Circulating endothelial progenitor cells (EPCs) are increased in conditions associated with ischaemia and can potentially support angiogenesis and vasculogenesis. EPC levels were also shown to predict outcome in patients with atherosclerotic vascular disease. We tested the hypothesis that circulating EPC can predict outcome in patients with congestive heart failure (CHF).

METHODS

EPC-colony-forming units were measured in the peripheral blood of 107 consecutive patients with CHF with New York Heart Association (NYHA) functional class II-IV. Serum levels of vascular endothelial growth factor (VEGF), N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and high-sensitivity C-reactive protein (hsCRP) were also measured. End points were defined as CHF-related hospital admissions and all-cause mortality.

RESULTS

Age (p = 0.01), diabetes mellitus (p = 0.002) and EPC levels (p = 0.02) were found to be independent predictors of all-cause mortality. EPC levels did not predict CHF-related hospitalisations. EPC levels correlated positively with NYHA (p = 0.05, r = 0.19), but did not correlate with VEGF, NT-pro-BNP or hsCRP. EPC levels did not differ by the aetiology of CHF.

CONCLUSIONS

EPC levels are independent predictors of all-cause mortality among patients with CHF.

A Commentary on Clinical Trials in Chronic Heart Failure

Heart failure is a common condition and becoming more common. Many treatments have been evaluated in large clinical trials during the last few decades. These trials can be criticized but do provide an evidence base for treatment, probably greater than for most other clinical conditions. Weaknesses exist in relation to age, ejection fraction, and gender. Most trials have included patients 10 years younger than those in the general population. There is little evidence for efficacy in patients with a near normal ejection fraction. Few women have been included in trials.

There Is Plenty of Room for Cardiac Resynchronization Therapy Devices Without Back-Up Defibrillators in the Electrical Treatment of Heart Failure

Patients with chronic heart failure might benefit from electrical therapy with a view to resynchronize the heart and improve its mechanical performance by cardiac resynchronization therapy (CRT) or to prevent the risk of sudden death by automatic defibrillation. These two therapies can be applied separately or with a combined device, the biventricular implantable cardioverter-defibrillator (CRT-D). There is currently no strong scientific evidence indicating that a CRT-D must be offered to all candidates for CRT. Plain common sense should limit the prescription of these costly devices for patients in need of secondary prevention or for younger patients without major comorbidities. The preferential choice of CRT pacemakers in the remainder of patients is currently a logical one.