Functional parameters identify more stage B heart failure

By Reuters Staff

NEW YORK (Reuters Health) - Testing for left ventricular (LV) functional disturbances, in addition to structural changes, can help identify patients with stage B heart failure (SBHF), new findings show.

"The inclusion of LV deformation and filling pressure expands the array of echocardiographic measures used for SBHF discrimination by adding major aspects of early myocardial impairment," Dr. Wojciech Kosmala of Wroclaw Medical University in Poland and colleagues wrote December 19 online in the Journal of the American College of Cardiology.

"The increasing potential of commercially available equipment for myocardial strain analysis extends the possibility of improving the recognition of SBHF at only a slight increase in duration of echo examination and overall cost of diagnostic procedures," they added.

Patients with SBHF have structural changes including left ventricular hypertrophy (LVH) and reduced left ventricular ejection fraction (LVEF), but remain asymptomatic, Dr. Kosmala and his team note. In stage A heart failure (SAHF), patients have HF risk factors such as hypertension, type 2 diabetes mellitus (T2DM), or obesity, but are also asymptomatic.

"The frequency of subclinical HF may exceed 50% in community members > 45 years of age; therefore, early recognition of SBHF offers the potential of altering disease progression therapeutically," the researchers write.

In the new study, they looked at 510 asymptomatic patients with T2DM (57%), obesity (69%), or hypertension (55%). Forty-eight percent were characterized as having SBHF based on functional or structural markers, while the rest were considered to have SAHF.

About half the patients with SBHF did not have significant left ventricular hypertrophy (LVH), the researchers found.

Patients with reduced LV strain (>-18%) had a peak VO2 of 21.0, versus 25.5 for patients without reduced LV strain. Peak VO2 was 19.0 for patients with increased LV filling pressure (E/e' > 13), versus 26.4 for those with normal LV filling pressure. Patients with LVH had a mean peak VO2 of 15.9, versus 26.0 for patients without LVH.

"Our findings indicate that not only structural (LV mass) but also functional (increased LV filling pressure, abnormal myocardial deformation) parameters contributed to lower exercise capacity in the asymptomatic phase of HF," Dr. Kosmala and colleagues write. "We propose that not only LVH, but also increased E/e' and/or decreased LV strain, should be considered when identifying SBHF."

In an editorial, Dr. Jae K. Oh and Dr. Barry A. Borlaug of the Mayo Clinic in Rochester, Minnesota, say the data have important implications for HF staging and for future trial design.

"In light of prior research," they write, "the findings from the current study strongly support the researchers' conclusion that abnormal strain and E/e' should be added to the current scheme by which we define SBHF."

"The fact that striking reductions in peak VO2 were observed in patients with abnormal strain and E/e' suggests that these patients may not be as asymptomatic as they (or we) think they are," the editorialists add.

"Confirmatory data from larger trials . . . will be important," they point out. But in the meantime, "Maybe the time has come to routinely apply these sensitive systolic and diastolic echocardiography parameters in our approach to patients with and at risk for HF."

The new study, they conclude, "urges us to do so sooner rather than later."

SOURCE: http://bit.ly/1wrGvwN and http://bit.ly/1BbAhFH

J Am Coll Cardiol 2014.

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