Structural and functional left ventricular remodeling in heart failure with cardiac resynchronization therapy

Congestive heart failure (CHF) is a clinical symptom complex characterized by fatigue, dyspnea, reduced exercise tolerance, lower extremity and pulmonary edema associated with abnormal handling of sodium by the kidney. There are an estimated 25-30 million patients with heart failure worldwide. Heart failure may occur at any age, but has a predilection for the elderly, occurring in 6-10% of subjects over the age of 65 years. The prevalence of CHF increases with advancing age, and as the population ages, the management of heart failure will attain epidemic proportions. Currently, CHF is the most common hospital discharge diagnosis in patients aged over 65 years, and the costs for this diagnostic-related group (DRG) in the USA alone have already exceeded $28 billion per year. failure was initially believed to be a relatively benign condition, but the annual mortality from diastolic heart failure ranges between 5% and 15% and the readmission rate for new-onset heart failure approaches 50% within the first 6 months.^1-4 The remaining 50-70% of patients present with systolic heart failure, and are clinically indistinguishable from patients with diastolic heart failure. It is important to identify patients with systolic heart failure, as they are eligible for additional therapeutic options such as cardiac resynchronization therapy (CRT), which has never been tested in patients with primary diastolic heart failure.