Cardiology

Despite advances in cardiac testing, noninvasive methodologies remain limited in their accuracy to (1) determine the etiology of chest pain; (2) detect preclinical coronary artery disease; and (3) track the progression of atherosclerotic lesions in native and revascularized coronary vessels.

Up to 100 sudden deaths occur among high school and college athletes each year in the United States, most commonly resulting from hypertrophic cardiomyopathy and other cardiac disorders. Studies have shown that preparticipation screening examinations that include a 12-lead electrocardiogram, which is not currently required in the United States, can identify asymptomatic athletes with hypertrophic cardiomyopathy. The current dilemma is how the United States, with its large population and emphasis on reducing health care costs, can realistically implement an effective prescreening process to identify these athletes.

When Hank Gathers collapsedon court during a college basketball game against Portland State on March 4, 1990, and later died, the event both jolted the national consciousness and set into motion changes in the athletic preparticipation screening process. Although another collapse had occurred just 4 months before, and an irregular heartbeat was detected at that time, Gathers was not compliant with the prescribed beta blocker and continued to play. An autopsy revealed that the 23-year-old Gathers suffered from cardiomyopathy.

An asymptomatic 66-year-old man with a history of nonobstructing carotid artery plaque and sleep apnea was referred for cardiac computed tomography (CT) scanning for risk stratification. He exercised on a regular basis with no symptoms and had normal results on at least 2 nuclear stress tests, the last test being performed only 12 months earlier.

In this issue, Schubert and Helenowski present a very dramatic instance of an increasingly common application of computed tomography (CT) coronary angiography—detection of an anomalous origin of the coronaries (page 40).

We performed a cost-utility analysis comparing treatment with aspirin, statins, and the combination of aspirin and statins among middle-aged men with no previous history of cardiovascular disease and with different underlying coronary artery disease (CAD) risk levels. Results showed that for men with a 10-year risk of CAD of 7.5% or higher, treatment with aspirin cost less and was more beneficial than no treatment. When the patient's 10-year risk of CAD before treatment was greater than 10%, adding a statin to aspirin treatment was cost effective.

Practicing cardiologists often joke about putting "statins" in the drinking water to stem the epidemic of atherosclerotic cardiovascular disease, but curiously, I don't believe that refers, even in jest, to a cocktail combination of drugs.

We performed cineventriculography, unenhanced echocardiography, contrast-enhanced echocardiography, and magnetic resonance imaging to define the presence of regional left ventricular wall motion abnormalities. Interobserver agreement in the analysis of regional wall motion abnormality was highest for contrast-enhanced echocardiography, followed by cineventriculography and cardiac magnetic resonance imaging; it was lowest for unenhanced echocardiography. Contrast-enhanced echocardiography also showed the highest accuracy in the detection of panel-defined regional wall motion abnormalities.

The lack of a reliable quantitative measurement analysis package for regional left ventricular wall motion is not new.

We assessed how well dobutamine stress echocardiography predicted morbidity and mortality in 2349 patients with diabetes mellitus over a follow-up period of 13.2 years. Results showed that age, failure to achieve the target heart rate, and the percentage of ischemic segments were independent predictors of both mortality and cardiovascular morbidity. Using clinical and stress echocardiographic parameters, a simple model for risk stratification was developed.

Cardiovascular disease is a leading cause of death for persons with diabetes, accounting for almost 80% of mortality in this group in the United States.

In the Prevention of Syncope Trial, we evaluated whether beta-blocker treatment with metoprolol was beneficial for the treatment of patients with vasovagal syncope. Results showed little evidence that metoprolol was effective in reducing the burden of syncopal symptoms. In a substudy analysis, neither age nor response to isoproterenol was useful in selecting which patients might benefit from metoprolol.

Neurocardiogenic syncope (vasovagal syncope) is the most common cause of loss of consciousness, ranging in various studies from 18% to 58% of all syncopal events.

Only one third of patients admitted to the hospital with acute myocardial infarction have normal renal function, and 17% have severe renal impairment. Decreased renal function is associated with the presence of comorbid conditions, underuse of effective treatments, and higher mortality. Renal function parameters should not only be included in scoring systems to assess risk levels, but patients with abnormal renal function should benefit from careful application of guidelines-recommended treatments for acute and long-term care.

Multiple observational and randomized trials support the finding that renal insufficiency has a significant, independent, graded effect on the risk of cardiovascular events and cardiovascular mortality.

More important than the choice of pharmaceutical agent in the treatment of elderly hypertensive patients is the achievement of goal blood pressure. Low-dose diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and calcium channel blockers are equally effective in reducing cardiovascular end points. Most patients will require 2 or more drugs to achieve target blood pressure, and physicians should feel comfortable prescribing 3 to 4 agents to a significant proportion of patients.

In their review, Gradman and Morsy emphasize the need to treat isolated systolic hypertension (ISH) and systolic/diastolic hypertension in elderly patients.

Studies have shown that elderly patients with heart failure are undertreated with evidence-based therapy, such as angiotensin-converting enzyme inhibitors and beta-blockers, although these therapeutic options appear to be effective in this age group. The risk of some side effects may be increased in elderly patients, and physicians should be aware of those when prescribing therapy. Cardiac resynchronization therapy is predicted to play a major role in future heart failure treatment, including in the elderly population.

Heart failure is the leading cause of hospitalization among Medicare beneficiaries, and it is the most costly diagnosis-related group by a factor of 2.