1. Beta Blockade and the Heart John Hakim, M.D Cardiology Fellow West Virginia University Division of Cardiology

2. Beta Blocker Heart Attack Trial n Randomized 4000 Patients to Placebo Vs. Propranolol n 20% Reduction in Mortality in Propranolol group n Despite a 17% rise in Triglycerides and a 6% rise in LDL

3. Beta Blockers in ACUTE MI n Beta Blockers Reduce pain, and reduce need for analgesics presumably by reducing ischemia n Most useful in patients with sinus tachycardia and HTN post MI

4. Beta Blockers in ACUTE MI Protocol (Braunwald) n Exclude patients with Heart Failure (10 cm rales above diaphragm), hypotension <90mmHG, Bradycardia <60 bpm, and Heart Block. n Metoprolol in three 5mg boluses q 5 min* n Stop if HR <60 or SBP <100mmHg n If stable, give oral metoprolol 50mg q6h x 2 days n Then switch to 100mg BID or Toprol XL (*IV esmolol useful in patient with relative contraindication.)

5. What not to give Post Acute MI n Unlike Beta Blockers, calcium antagonists are of little value in AMI and may, in fact, be hazardous.

6. Effects of Beta Blockers Post MI n Immediate: reduces cardiac index, heart rate and blood pressure. Net effect is to reduce myocardial oxygen consumption/minute/beat. (Reduces Chest Pain) n Reduces infarct Size in Acute MI n Diminishes circulating levels of free fatty acids by antagonizing lipolytic effects of catecholamines. (FFA augment O 2 consumption and increases incidence of arryhthmias.

7. Effects of Beta Blockers Post MI (Pre-Thrombolytic Era) n ISIS-1 –16,000 patients randomized –reduction of mortality among patients randomized to IV atenolol Vs. placebo. n Meta analysis of 27 trials (27,000+ patients) IV followed by oral beta blockers –15% relative reduction in mortality, non fatal reinfarction, and nonfatal cardiac arrest

8. Effects of Beta Blockers Post MI n TIMI-II trial (Thrombolytics in MI) –Recurrent ischemia and reinfarction were reduced by immediate vs. delayed use of metoprolol. –mortality and LV function were not improved by immediate metoprolol. –Therefore beta-blockers are beneficial, but may not enhance the salvage of myocardium due to early reperfusion.

9. Effects of Beta Blockers Post MI Current Recommendations n Patients with hyperdynamic state ( sinus tachycardia, HTN, no CHF or bronchospasm, no heart block) n Patients seen in the first 4 hours of their MI n Regardless of whether thrombolytics are used n Beta-Blockers indicated for people with persistent or recurrent ischemic pain

10. Beta Blockers and Idiopathic Dilated Cardiomyopathy n Chronic Beta-Blockers increase the number of Beta adrenergic receptors on the Heart n Reduced ischemia and more efficient oxygen utilization (Study done w/ metoprolol) n Detectable improvement in Cardiac Output (and EF) after three months. n Long term structural changes of decline in LV volume and Mass after 12-18 months.

11. Other Beta Blocker Indications n Arrhythmias associated with thyrotoxicosis, pheochromocytoma –excess catecholamine state. n Arrhythmias initiated by excercise or emotion often respond to propranolol n Metoprolol may be helpful in controlling rate of multifocal atrial tachycardia

12. Question: n Peri-operative myocardial ischemia is the single most important reversible risk factor for mortality and cardiovascular complications annually. n Is there any way to prevent perioperative myocardial ischemia during non cardiac therapy?

13. Perioperative Cardiovascular Morbidity and Mortality n In patients who are at risk for coronary artery disease who must undergo non- cardiac surgery, treatment with atenolol during hospitalization can reduce mortality and the incidence of cardiovascular complications for as long as 2 years after surgery. (N Eng J Med 1996;335:1713-20)

14. Perioperative Cardiovascular Morbidity and Mortality n In patients with CAD standard practice is to control heart rate pre-op and intra-op. n Post-op tachycardia may precipitate ischemia n Beta-blockade can modulate the post-op sympathetic response. n Preventing ischemia prevents morbidity and mortality.