Age-adjusted hospitalization rates for heart failure increased considerably throughout the western world in the 1980s and early 1990s, as documented by reports from the Netherlands, New Zealand, Scotland, Spain, Sweden, and the USA. The âœepidemicâ appeared to peak in 1993/4.
In their analysis of trends in hospitalization for heart failure in Scotland from 1990 to 1996, Stewart et al found that rehospitalization increased by 56% and accounted for 23% of all hospitalizations in 1996.
In the Studies Of Left Ventricular Dysfunction (SOLVD) registry, factors related to 1-year mortality or hospital admission for congestive heart failure included age, ejection fraction, diabetes mellitus, atrial fibrillation, and female gender. There was no difference in mortality associated with congestive heart failure among blacks and whites, but hospital admissions for heart failure were more frequent in blacks. Contributors to preventable readmission include drug and/or diet noncompliance, inadequate discharge planning or follow-up, a failed social support system, and failure to seek medical attention promptly when symptoms recur. Heart failure patients who are discharged home are at greater risk of readmission than those discharged to a secondary facility. Ideally, those at high risk for hospitalization should be identified during the hospital course and selectively targeted for measures aimed at reducing readmission rates.
Evangelista et al showed that noncompliance with tobacco and alcohol warnings dramatically increases the risk for multiple hospital readmissions in heart failure patients. Diet and drug noncompliance also triggers decompensation. Interventions targeted at maximizing patient compliance can greatly reduce the rehospitalization rate.
Elderly patients are at increased risk of early rehospitalization: up to half may be readmitted in the first year. Behavioral factors, including diet and drug non-compliance, and social factors, such as social isolation, are common contributors, suggesting that many such readmissions could be prevented.
Comorbidity and previous hospitalizations
In a consecutive cohort of patients hospitalized for decompensated heart failure, Harjai et al identified chronic obstructive pulmonary disease (COPD) and a history of any-cause hospitalization in the preceding 6 months as the strongest correlates of early readmission. They proposed a simple risk stratification, patients with no history of hospitalization being at low risk, and those with a history of COPD and recent and/or prolonged hospitalization as at highest risk. Because COPD entails a variable degree of pulmonary hypertension, even a small amount of fluid overload may precipitate severe dyspnea and hospitalization with clinical patterns of heart failure. High blood urea nitrogen at the index hospitalization, an indicator of severe prerenal compromise, was also independently associated with an increased risk of any-cause readmission.
Heart failure risk factors and severity of left ventricular dysfunction
In their retrospective analysis of hospitalizations for heart failure in a center serving predominantly Afro-American patients, Ofili et al found that most patients had a history of hypertension and over half had uncontrolled hypertension at admission. Diabetes, angina, and echocardiographic dyskinesia or akinesia were independently associated with increased hospitalization. Other studies have shown correlations with heart failure of ischemic origin, higher New York Heart Association (NYHA) class, and an ejection fraction <40%.
Suboptimal drug therapy
Calcium channel antagonists, a-blockers, and hydralazine have all been associated with increased rehospitalization for heart failure. With the first-gen-eration calcium channel antagonists, the probable cause was their negative inotropic potential in patients with left ventricular dysfunction. Higher rates of hospitalization for pulmonary edema marked the first few months of treatment in the Prospective Randomized Amlodlpine Survival Evaluation (PRAISE) trial. The mechanism may involve the acute hemodynamic effects of these agents when combined with other hypotensive agents, compounded by associated fluid retention due to vasodilator therapy.
Optimizing the diuretic dosage may reduce readmission rates for decompensation. Although physical examination may suggest that many heart failure patients are in optimal fluid balance, invasive hemodynamic evaluation can show markedly elevated intracardiac pressures. These patients respond to more intensive diuresis with improved exercise tolerance. Clinical trials have shown that both angiotensin-converting enzyme (ACE) inhibitors and (3-blockers reduce chronic heart failure-related hospitalizations, each by roughly one third. In the Randomized ALdactone Evaluation Study (RALES), treatment of NYHA class IV patients with spironolactone conferred a 30% reduction in both the risk of death and the number of hospitalizations at 24 months. Thus, patients in advanced heart failure are being undertreated if they are not receiving an antialdosterone drug.
In the recent Valsartan in Heart Failure Trial (Val-HeFT), addition of valsartan to ACE inhibitor or [3-blocker therapy did not lower mortality but did lower rehospitalization for heart failure, whereas outcome was unchanged (or poorer) on the triple combination of [3-blocker, ACE inhibitor, and angiotensin receptor blocker vs the double combination of (3-blocker and ACE inhibitor. Thus therapy may be considered suboptimal if patients are given a [3-blocker or ACE inhibitor in isolation. Instead, an ACE inhibitor needs to be combined with a (3-blocker or (in the event of intolerance or contraindications) an angiotensin receptor blocker, or a (3-blocker with an angiotensin receptor blocker.
Digoxin had no effect on mortality or quality of life in the Digoxin Investigators Group (DIG) trial, but it lowered hospitalization due to worsening heart failure vs placebo.
Intervention against left ventricular dysfunction before the onset of symptomatic chronic heart failure may attenuate disease progression, thus reducing both the incidence of chronic heart failure and the number of hospitalizations.