Baltimore, MD - The severity of subclinical carotid atherosclerosis by ultrasound is independently and inversely related to regional systolic and diastolic myocardial function measured by magnetic resonance imaging (MRI), suggested a report from a large, ongoing population-based study [1].

"We found consistent associations between carotid intima-media thickness [IMT] and decreased myocardial systolic and diastolic strains measured by MRI tissue tagging, which is considered to be the gold-standard technique for regional LV functional assessment," write Dr Verônica RS Fernandes (Johns Hopkins University, Baltimore, MD) and associates. Carotid IMT by ultrasound is a common surrogate for coronary disease severity.

The finding from the Multi-Ethnic Study of Atherosclerosis (MESA) is the literature's first in asymptomatic persons without a history of clinical CV disease, according to their report in the June 20, 2006 issue of the Journal of the American College of Cardiology.

This study challenges the notion that atherosclerosis . . . impairs cardiac function by causing discrete clinical episodes of myocardial infarction or ischemia.

"This study challenges the notion that atherosclerosis . . . impairs cardiac function by causing discrete clinical episodes of myocardial infarction or ischemia," the group writes. "Because asymptomatic global LV dysfunction is considered to be a subclinical marker of heart failure because of its frequent progression to symptomatic CHF, the IMT-related alterations of regional LV function reported in this study could represent the earliest signs of myocardial functional impairment in the heart-failure continuum."

The investigation's findings of "unexpected" reductions in regional myocardial function "suggest that we should perhaps implement preventive strategies more vigorously and earlier than we thought," said Fernandes, as quoted in a press release from the journal's publisher.

Dr Margaret M Redfield (Mayo Clinic, Rochester, MN) told heartwire that it's unclear how the report's findings and conclusions relate to heart failure. It makes some sense that progression of carotid disease would be associated with subtle changes in LV function, she said. On the other hand, she observed, the study's myocardial strain and strain-rate measures of ventricular function are far less direct than a current standard, LVEF.

This use of cardiac MRI, she said, is still in the realm of research. "To my knowledge, there's been no study that has shown a progression from decreased strain [to] decreased EF."

The multicenter MESA study, designed to explore possible ways to detect incipient CAD, among other goals, started out with 6814 persons in the community who were free of CVD at entry from 2000 to 2003 [2]. The cohort included large numbers of not only whites but blacks, Hispanics, and Chinese.

The links between cardiac and vascular disease . . . may have quite a bit of significance in patients who have heart failure with normal ejection fraction—it's not just a disease of the heart, it's a disease of the heart and vessels.

In the current report's 500 MESA subjects who were initially without clinical CV disease, the mean carotid IMT was 0.86 mm. Compared with women, men had a 69% increased likelihood of being among the 21% of the group who had an IMT >1 mm.

Increased carotid IMT was significantly correlated with strain-marker measurements indicating reduced systolic function (p<0.05) in the lateral, anterior, and septal myocardial walls, but not in the inferior wall. It had the same relationship with the strain-related indicator of diastolic contraction (p<0.01) in the lateral, inferior, and septal myocardial walls, though not the anterior wall.

The systolic and diastolic findings were independent of a range of variables, including age, race, body-mass index, systolic and diastolic pressures, lipoprotein cholesterol levels, and medications for hypertension, dyslipidemia, and diabetes.

The links between cardiac and vascular disease highlighted in the study, according to Redfield, "may have quite a bit of significance in patients who have heart failure with normal ejection fraction—it's not just a disease of the heart, it's a disease of the heart and vessels." But to her, she added, the report is significant for "extending our understanding of that interaction in a way that is very basic," though not currently clinically relevant.