Cardiology

We examined the relationship between the 6-minute walk test and self-perceived changes in symptoms in 1077 elderly patients with chronic heart failure. We found that changes in 6-minute walk test distance were sensitive to changes in self-perceived symptoms of heart failure.

In an era when high-tech procedures are becoming increasingly common in cardiology, it's refreshing to see continued interest in one of the lowest-tech diagnostic/prognostic procedures currently available: the 6-minute walk test.

We evaluated the effects of rate control treatment versus sinus rhythm restoration and maintenance in patients with persistent atrial fibrillation in a substudy of the Rate Control Versus Electrical Cardioversion (RACE) trial. Rhythm control treatment was associated with greater cardiovascular morbidity and mortality in women. Because treatment did not improve quality of life in these patients, rate control may be considered as first-choice therapy for women.

IIn their review, Rienstra and Van Gelder summarize their findings from the Rate Control Versus Electrical Cardioversion (RACE) study.

The previous installment of this series on clinical research highlighted some im­portant fundamentals in cohort studies and randomized controlled trials (RCTs). In this article, additional issues that are critical to the understanding of RCTs are discussed, including causal inference, the use of surrogate measures, and the principle of intention to treat (ITT).

It takes a gutsy person to sign up for a plenary session with that title. From the moment she took the podium, Grace Anne Dorney Koppel captivated a small audience with her moving story of her struggle with chronic obstructive pulmonary disease (COPD) and its many co-morbidities. With steely resolve, she challenged the physicians in the audience to step up their efforts to diagnose and treat a disease that currently affects more than 24 million Americans.

Ballistic injuries may be diagnostically challenging because of the unpredictable trajectory of projectiles and the possibility of their migration via the enteric, vascular, genitourinary, or central nervous systems.

We examined the prevalence and risks associated with undiagnosed diabetes mellitus among more than 7000 patients who had undergone coronary artery bypass graft surgery. At the perioperative and postoperative stages, patients with undiagnosed diabetes showed a significantly higher morbidity and mortality rate.

Lauruschkat and colleagues entitled their article "Undiagnosed diabetes mellitus in coronary artery bypass graft sur­gery."

We assessed the relationship between high-density lipoprotein (HDL) cholesterol level and carotid plaque progression in 1952 men and women with preexisting carotid atherosclerosis over a period of 7 years. The HDL cholesterol level was inversely related to plaque growth. The plaques that became more echogenic during follow-up had a lower growth rate compared with those that became more echolucent. These findings suggest that HDL cholesterol stabilizes plaques and counteracts their growth by reducing their lipid content and inflammation.

The report by Johnsen and colleagues details the changes in plaque composition and size as defined by duplex ultrasound at 2 time points 7 years apart

Standard congestive heart failure treatment begins with an angiotensin-converting enzyme (ACE) inhibitor to which a beta-blocker is added once the target dose of the ACE inhibitor has been reached. We compared morbidity and mortality between standard treatment and treatment using the reverse sequence, that is, the beta-blocker bisoprolol was given to patients first, followed by the ACE inhibitor enalapril. Results showed that both sequence strategies were safe and effective, with a survival trend in favor of the bisoprolol-first strategy.

The development of new and innovative mechanical and pharmacologic therapies for the broad spectrum of cardiovascular disease has led to dramatic changes in the makeup of clinical practice.

We examined the association between plasma N-terminal pro-brain natriuretic peptide (Nt-pro-BNP) levels and the occurrence of cardiac events, including cardiogenic shock and mortality, among hospitalized diabetic patients with acute myocardial infarction. Nt-pro-BNP level was shown to be a reliable predictor of outcome in this group of patients.

Diabetes is a potent risk factor for adverse outcomes following acute myocardial infarction,1 but the mechanisms responsible for this association are not well understood.

In a separate analysis of patients enrolled in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study, thin patients and those with moderate-to-severe obesity were at increased risk for cardiovascular events. These results indicate that patients at the low anda high ends of the body size spectrum should be treated aggressively to lower the risk of cardiovascular events.

The observed relationship linking obesity, severity of hypertension, and increase in cardiovascular risk was traditionally thought to emanate from the increase in circulatory volume, persistently increased systemic resistance from obesity, and clustering of major cardiovascular risk factors (eg, hypercholesterolemia and diabetes mellitus) among obese patients.

We evaluated how well patients taking spironolactone were monitored for hyperkalemia, as well as the association between spironolactone and hyperkalemia. Only two thirds of patients received testing for serum potassium and creatinine levels, and higher baseline serum creatinine levels predicted a high risk of hyperkalemia. These results indicate that appropriate patient selection and close monitoring are essential, especially for patients with renal impairment.

In 1999 Pitt and colleagues published the results of the RALES trial, an important study showing that the addition of a relatively small dose of the aldosterone antagonist spironolactone to a regimen that included angiotensin-converting enzyme (ACE) in­hibitors for patients with severe congestive heart failure (NYHA Class III-IV) had a striking benefit on mortality

We conducted 2 feasibility studies to assess the performance and safety of the percutaneous left atrial appendage (LAA) transcatheter occlusion system for the prevention of stroke in high-risk patients with nonrheumatic atrial fibrillation. Results showed that percutaneous LAA occlusion can be performed using the device at acceptable risk. This procedure may be particularly useful for patients at increased risk of ischemic stroke with a contraindication to anticoagulation therapy.