Worse diastolic LV dysfunction predisposes to HF in diabetics

Falcão-Pires I. Circulation. 2011;124:1151-1159.

Issue: October 2011

Worse diastolic left ventricular dysfunction predisposes patients with aortic stenosis and diabetes mellitus to HF and derives from more myocardial fibrosis, more intramyocardial vascular advanced glycation end-product deposition and higher cardiomyocyte resting tension, according to a study.

There were 62 patients with symptomatic aortic stenosis included in the study. Patients had to be referred for surgical valve replacement and had to be operated on between January 2006 and December 2008 to be included in the study. Patients were subdivided into two groups: patients with aortic stenosis and no diabetes mellitus (AS) and patients with aortic stenosis and diabetes mellitus (AS-DM).

Researchers implanted preoperative Doppler echocardiography and hemodynamics into patients, measured resting tension by stretching isolated cardiomyocytes, and expression and phosphorylation of titin isoforms were analyzed with gel electrophoresis. Myocardial collagen volume fraction and myocardial advanced glycation end-product disposition were measured by histomorphometry and immunohistochemistry.

Researchers found that higher LV end-diastolic pressure (P=.04) was evident by reduced LV end-diastolic distensibility in AS-DM patients. Higher LV end-diastolic pressure also attributed to higher myocardial collagen volume fraction (P<.001), more advanced glycation end-product deposition in arterioles, venules and capillaries (P=.03), and higher resting tension (P=.04).

Larger LV mass index (P<.001) showed that LV hypertrophy was present in AS and AS-DM patients. According to the study, a ratio of LV mass index to LV end-diastolic volume index was also larger for AS and AS-DM patients (P<.001). Higher LV end-diastolic pressure (P=.04) at a comparable LV end-diastolic volume index showed that end-diastolic LV distensibility was lower in AS-DM patients.

When looking at collagen volume fraction, researchers found that it rose from 10.2 ± 1.2% in AS patients to 19.1 ± 6.3% in AS-DM patients (P=.013) in picrosirius red-stained sections, and from 12.9 ± 1.1% in AS patients to 18.2 ± 2.6% in AS-DM patients (P<.001) in hematoxylin and eosin-stained sections. In a multiple regression analysis that included collagen volume fraction and AS patients, collagen volume fraction correlated with LV end-diastolic pressure (P=.005), according to the study.

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