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Aortic valve replacement in patients with aortic valve stenosis improves myocardial metabolism and diastolic function
H P Beyerbacht1, H J Lamb, A van Der Laarse
1Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 2A Leiden, the Netherlands.
Purpose:
To evaluate whether functional and metabolic changes recover after aortic valve replacement (AVR).
Materials And Methods:
Eighteen men with aortic valve stenosis (mean pressure gradient +/- SD, 79.9 mm Hg +/- 15.1) underwent magnetic resonance (MR) imaging and phosphorus 31 MR spectroscopy. In nine patients who underwent AVR, MR imaging and spectroscopy were repeated 40 weeks +/- 12 after AVR. Ten age-matched healthy men were control subjects.
Results:
Before AVR, the myocardial phosphocreatine (PCr)-to-adenosine triphosphate (ATP) ratio in the 18 patients was 1.24 +/- 0.17 and 1.43 +/- 0.14 in the control group (P <.01). In nine patients who underwent follow-up MR spectroscopy, the ratio increased from 1.28 +/- 0.17 to 1.47 +/- 0.14 (P <.05) following AVR. Before AVR, early acceleration peak corrected for cardiac output was (0.043 +/- 0.008) x 10(-3) sec(-1) in patients and (0.081 +/- 0.033) x 10(-3) sec(-1) in the control group (P <.05). After 40 weeks +/- 12, the mean early acceleration peak corrected for cardiac output in the nine patients increased significantly to (0.055 +/- 0.006) x 10(-3) sec(-1) (P <.05), although it was still significantly lower than that of the control group (P <.05). Before AVR, a significant correlation was found between the myocardial PCr-ATP ratio and left ventricular diastolic function (n = 18; P <.05).
Conclusion:
Severe aortic valve stenosis leads to a decreased myocardial PCr-ATP ratio and impairment of left ventricular diastolic function; following AVR, the ratio normalizes completely, whereas function improves significantly. There is an association between altered myocardial high-energy phosphate metabolism and impaired left ventricular diastolic function.