Beta-blockers improve symptoms and clinical status and decrease mortality and hospitalization in heart failure patients in New York Heart Association class II (mild-to-moderate) to IV (severe) with a left ventricular ejection fraction below 35% to 40%.
Heart failure severity
Few controlled data are available in asymptomatic left ventricular systolic dysfunction, a typical example of which is the postinfarction patient. However, (3-block-ers significantly decrease mortality in such patients, especially those with a history of heart failure.
We owe our data in severe heart failure to the recent CarvedilOl ProspEctive RaNdomlzed Cumulative Survival (COPERNICUS) trial in the sickest heart failure population of any p-blocker trial to date (19.7% annual placebo mortality). Carvedilol not only decreased all-cause mortality by 35%, but its tolera-bility was excellent. It was also effective in the sickest COPERNICUS subgroup (ejection fraction <15% and multiple hospitalizations). Similarly, analysis of the severe heart failure subgroup in the Metoprolol CR/XL Randomized Intervention Trial in Heart Failure (MERIT-HF) showed that metoprolol reduced overall mortality by 39% and hospitalizations for exacerbated heart failure by 44%. Heart failure etiology P-Blockers are equally effective in heart failure caused by coronary artery disease or idiopathic dilated cardiomyopathy. However, little is known about their efficacy in heart failure due to other causes, such as valvular disease. Results from the recent Carvedilol Post-Infarct Survival Control in Left Ventricular Dysfunction (CAPRICORN) study suggest that in the absence of contraindications, especially ongoing fluid retention, carvedilol should be initiated as early as possible for postinfarction left ventricular dysfunction and continued in the long term. Adding carvedilol to conventional postinfarction therapy decreased the frequency of recurrent nonfatal infarction and all-cause and cardiovascular mortality. These benefits are additional to those of evidence-based treatments for myocardial infarction, including angiotensin-converting enzyme (ACE) inhibitors. (i-Blockers are also effective in patients who do not tolerate ACE inhibitors. Relative contraindications (3-Blockers also improve survival in postinfarction patients with chronic obstructive pulmonary disease. Despite concerns that p-blockers might mask signs of hypoglycemia, they are particularly effective in decreasing morbidity and mortality in diabetics. Mild-to-moderate renal or hepatic dysfunction does not generally affect their tolerability; however, greater caution is recommended in the titration phase, with more attention to side effects, especially if the dysfunctional organ is responsible for eliminating the P-blocker concerned. Clinical stability The most important factor influencing P-blocker tolerability in heart failure is clinical stability. Over 90% of patients who have been clinically stable in the previous weeks, with no evidence of fluid retention, tolerate therapy initiated at very low doses and increased in 2-weekly increments. Which patients should not be given p-blockers? Absolute contraindications to P-blockers: â¢ Bronchial asthma in a patient sensitive to (3-agonist inhalation. â¢ First degree atrioventricular (AV) block (PQ interval >28 s) or second- or third -degree AV block (unless paced).
â¢ Bradycardia (heart rate <50 bpm).
â¢ Hypotension (<90 mm Hg systolic).
â¢ Acute heart failure decompensation including:
- Significant fluid retention requiring intensive diuresis.
- Intravenous heart failure therapy.
- Hospitalization for heart failure.
â¢ Severe peripheral vascular disease with threatened viability of extremities (vasospasm, rest pain, trophic skin lesions).
Indications requiring special attention:
â¢ Diabetes: P-blockade can mask signs of hypoglycemia. BUT P-blockers can have greater benefits in diabetics than in the general population.
â¢ Organ failure, in an organ responsible for eliminating the P-blocker concerned.
Consensus recommendations for the management of chronic heart failure. On behalf of the membership of the advisory council to improve outcomes nationwide in heart failure. Am J Cardiol. 1999;83:1 A-38A.
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Pozzi R. [True and presumed contraindications of beta blockers. Peripheral vascular disease, diabetes mellitus, chronic bronchopneumopathy]. Ital Heart J. 2000,1 (suppl 8); 1031-1037.
Task Force for the Diagnosis and Treatment of Chronk Heart Failure. European Society of Cardiology. Eur Heart J. 2001. 22:1527-1560. Tavazzi L, Opasich C. Scompenso cardiaco giomo per giomo [Heart failure day by day], 1999: 42-54; 61.
J3-blocker; indication; contraindication; management