Inverse shift in serum polyunsaturated and monounsaturated fatty acids is associated with adverse dilatation of the heart.

BACKGROUND

Cardiac dilatation is associated with impaired pump function, progression of heart failure and electrical instability. Risk of sudden death is associated with a low blood level of n-3 polyunsaturated fatty acids.

OBJECTIVE

The hypothesis was, therefore, addressed that left ventricular dilatation as assessed by echocardiography is associated with a reduced serum polyunsaturated fatty acid level.

METHODS

Fatty acids were determined with gas chromatography/mass spectrometry in serum of 308 patients with dilative heart failure unrelated to myocardial infarction (age 48 (SD12) years, NYHA class 2.2 (0.6), ejection fraction 31% (10%)).

RESULTS

The extent of left ventricular dilatation as assessed by left ventricular end-diastolic diameter was associated with a reduction of both n-3 and n-6 polyunsaturated fatty acids. The n-3 docosahexaenoic acid (1.0% (0.5%) vs 1.3% (0.6%), p<0.001) and the n-6 arachidonic acid (4.6% (1.8%) vs 5.2% (1.9%), p<0.01) were reduced in patients with left ventricular dilatation (end-diastolic diameter, 68-90 mm, upper tertile vs 48-61 mm, lower tertile). By contrast, monounsaturated fatty acids were increased (the n-9 oleic acid 26.1% (4.8%) vs 23.9% (4.8%), p<0.01). A low docosahexaenoic acid (0.01-0.9%, lower tertile vs 1.4-3.1%, upper tertile) was associated with greater left ventricular dilatation (end-diastolic diameter, 67 (8) vs 63 (7) mm, p<0.001). The cut-off for the absence of severe dilatation (end-diastolic diameter >70 mm) was set at >1.24% docosahexaenoic acid. In our sample, the negative-predictive value for severe dilatation was 91% and sensitivity was 84%.

CONCLUSIONS

Docosahexaenoic acid provides a new sensitive biomarker for monitoring and detecting severe left ventricular dilatation in heart failure patients.