Author + information
- Keiichiro Yoshinaga,
- Hiroshi Ohira,
- Ichizo Tsujino,
- Osamu Manabe,
- Takahiro Sato,
- Chietsugu Katoh,
- Katsuhiko Kasai,
- Yuuki Tomiyama,
- Noriko Oyama-Manabe,
- Masaharu Nishimura and
- Nagara Tamaki
Elevated pulmonary arterial pressure may increase right ventricular (RV) oxidative metabolism in patients with pulmonary hypertension (PH). A pulmonary hypertension (PH)-specific vasodilator decreases pulmonary arterial pressure. However, it is not clear whether such a treatment favorably affects RV myocardial oxidative metabolism. The purpose of this study was to investigate the possible impacts of the intensified PH-specific vasodilator therapy on myocardial energetics using 11C acetate PET.
Nine PH patients who had additional or increased doses of PH-specific vasodilator (s) based on ESC/ERS guidelines for diagnosis and management of PH were compared with 5 PH patients who had no treatment modification (control group). Pulmonary vascular resistance (PVR) was calculated based on right heart catheterization data. Ventricular function was assessed using magnetic resonance imaging (MRI). Dynamic 11C-acetate PET was used to simultaneously measure RV and left ventricular (LV) oxidative metabolism (kmono). RV myocardial work per oxygen consumption index was calculated as follows [RV stroke volume index (SVI) / RV kmono]. Measurements were performed at baseline and after 10±6 months follow-up.
Intensified PH therapy group tended to reduce PVR compared with control group (−20.6±41.7 vs. −3.4±33.2%, P=0.29). Intensified PH therapy significantly reduced RV oxidative metabolism (0.044±0.008 to 0.039±0.007/min, P=0.002) while increasing SVI (31.4±10.1 to 39.3±9.6 mL/m2, P=0.017). As a result, the intensified therapy significantly improved the RV work/oxygen consumption index (730.8±253.6 to 1038.5±262.7 mL/min·m2, P<0.001). There was no significant change in LV kmono in this group (P=0.35. The control group did not change in these parameters (RV kmono: P=0.15, RV work/oxygen consumption index: P=0.69).
Intensified PH-specific vasodilator therapy led to a reduction in right ventricular oxidative metabolism and a significant improvement in right ventricular work per oxygen consumption index in patients with pulmonary hypertension. These effects may contribute to the benefits of the intensified PH-specific vasodilator therapy.
West, Room 3001
Sunday, March 10, 2013, 10:45 a.m.-11:00 a.m.
Session Title: Nuclear Cardiology and PET: Pushing the Boundaries
Abstract Category: 21. Imaging: Nuclear
Presentation Number: 926-3
- 2013 American College of Cardiology Foundation