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.