NEWS ARCHIVES

Carvedilol: New Hope For Your Patients With Severe Heart Failure?
By Stanley R. Berger, MD, FACC

Minimally Invasive Coronary Artery Bypass Grafting
By Gerald L. DeVaughn, MD, FACC

Acute Myocardial Infarction Still Major Health Threat
by Stanley R. Berger, M.D.

Acute Myocardial Infarction Still Major Health Threat

Acute myocardial infarction (AMI) costs roughly 225,000 American lives each year and
much of this loss could be averted by early detection and treatment.1 A significant
proportion of individuals who present with AMI are not candidates for thrombolytic
therapy. Also, primary PTCA is often unavailable or not indicated for this group.
Therefore, appropriate medical intervention is more urgent because this group cannot
benefit from early reperfusion strategies.

In the newly released ACC/AHA Guidelines for Acute Myocardial Infarction,1 two very important medical therapies are recommended, in addition to aspirin, for patients who do
not receive thrombolytic therapy: beta-blockers within 12 hours if there are no contraindications and ACE inhibitors within 24 hours for those with anterior infarctions,
an EF < 40% or clinical CHF from systolic dysfunction. Calcium channel blockers are discouraged in the routine treament of AMI, particularly in patients with LV dysfunction
or CHF. Even in non-ST elevation (non-Q wave) infarction, diltiazem or verapamil should
be used only if beta-blockers are contraindicated and in the absence of CHF, LV
dysfunction or contraindication to calcium channel blocker use.

1. Ryan TJ, Anderson JL, Antman EM, Braniff BA, Brooks NH et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). J Am Coll Cardiol 1996;28:1328-1428.

Summer 1996 Volume I, Number 2
Minimally Invasive Coronary Artery Bypass Grafting.

There is now available a surgical alternative to catheter-based revascularization that is significantly less costly and debilitating to patients when compared to traditional coronary artery bypass surgery. The minimally invasive technique can be used for grafting proximal lesions of the left anterior descending or right coronary arteries.

Instead of the usual extensive median sternotomy required for the conventional procedure,
a 2- to 3-inch parasternal incision is made on the left or right, according to which artery
needs attention. After removing either the third or fourth costal cartilage, the internal mammary artery is dissected to the pedicle.

Significant reduction in post-op recovery time can be attributed to the ability to perform coronary anastomosis without the use of the cardiopulmonary bypass pump or cardiac
cooling. Beta-blocking to heart rates of 40 beats-per-minute facilitates successful
anastomosis.

There has been no mortality and no significant morbidity associated with this procedure in reported series (1,2). Dr. Mwazhuwa Kuretu from the Division of Cardiothoracic Surgery
at Allegheny University Hospital, Center City (formerly Hahnemann University Hospital) believes that minimally invasive surgery is indicated for the treatment of symptomatic
patients with total occlusion of the left anterior descending coronary artery and other
lesions that are not technically suitable for catheter revascularization. He has been able to extubate patients in the recovery room and says that discharge is possible in 24 to 48 hours.

-Gerald DeVaughn, M.D.

References:

1. Robinson et al : Journal of Cardiovascular Surgery, 1995; 10:529-536.

2. Benetti et al : Journal of Cardiovascular Surgery, 1995; 10: 620-625.

New Feature ! - "Did You Know...?"

DID YOU KNOW ....??

In mitral valve prolapse, the decision regarding antibiotic prophylaxis rests on the
physical exam findings of a click and a significant murmur, not primarily on echocardiographic findings....

Diastolic dysfunction is not a contraction but a relaxation problem of the myocardium
leading to elevated diastolic pressures, congestive symptoms and occasionally frank
pulmonary edema....

The terms transmural and subendocardial infarction are not as accurate as the terms
Q wave and non-Q wave infarction since pathological studies have demonstrated that
not all Q wave infarcts are transmural and not all non-Q wave infarcts are subendocardial...

Spring 1996 Volume I, Number 1
Carvedilol: New Hope For Your Patients With Severe Heart Failure?

Your patient has symptomatic congestive heart failure and an evaluation reveals dilated cardiomyopathy with an ejection fraction less than 35%. The patient is not a candidate
for heart transplantation and there is no indication for revascularization.

Despite best therapy with digoxin, diuretics and an ace-inhibitor, your patient continues
to have mild and, at times, moderate to severe signs and symptoms of heart failure and
you know the prognosis is not good.

We all often see this scenario in our practices but recent multicenter clinical trials have generated great excitement for a new agent in the treatment of heart failure - Carvedilol.

Carvedilol is a beta blocking agent with important additional actions including
vasodilation by alpha-adrenergic receptor blockade and potent antioxidant effects.

At the annual scientific sessions of the American Heart Association in November 1995, investigators reported dramatic results with this medication treating patients with NYHA
Class II, III and IV heart failure and EF < 35% (1). In a large multicenter trial enrolling 1,094 patients already taking angiotensin-converting-enzyme inhibitors, digoxin and
diuretics, patients treated with Carvedilol had an overall mortality reduction of 67%
compared with placebo. This was a reduction from 7.8% to 3.0% (1) and an absolute mortality reduction of 48 patients per 1000 treated. This result is extraordinary in this population of patients and prompted early termination of the trial.

Yet, as with all early trials of a new treatment option, further analysis of the data is
warranted before we can advocate widespread use of Carvedilol in heart failure patients.
One important aspect brought out by earlier trials of beta blocking agents in patients with congestive heart failure is the chance that, in some patients, the congestive symptoms
worsen with treatment by a beta blocker. Also, in the trials with Carvedilol, the dose was titrated up typically from 6.25mg to as much as 50mg twice a day (1). The most effective dosing regimen remains uncertain. Finally, although risk reduction in this trial was seen
in all NYHA classes of heart failure at the level of roughly 67% decrease in mortality,
and in patients with and without ischemic heart disease (1), further evaluation of the
extent of side effects, such as the reported increase in dizziness and advanced heart
block (2), is warranted. Carvedilol is presently FDA approved only for the treatment of hypertension. Should further studies bear out the promising early data outlined above, Carvedilol may become an important additional agent leading to improved outcome for patients wth dilated congestive cardiomyopathy. - Stan Berger, M.D.

References:

1. Prescott LM. Carvedilol dramatically reduces mortality in heart failure. Internal Medicine World Report 1996 Jan 1-14; 11(1):7.

2. Krum H, Sackner-Bernstein JD, Goldsmith RL, Kukin ML, et al. Double-blind, placebo-controlled study of the long-term efficacy of carvedilol in patients with severe chronic heart failure. Circulation 1995 Sep 15; 92(6):1499-506.