Quantifying Pathologic Left Ventricular Hypertrophy by Mismatch of Coronary Artery Blood Volume to Myocardial Mass - The 65th Annual Conference of the Israel Heart Society & The Israel Society of Cardiothoracic Surgery, 24-25 April 2018

Ashraf Hamdan Cardiology Department, Rabin Medical Center, Israel Mithal Nassar Cardiology Department, Rabin Medical Center, Israel Daniel Monakier Cardiology Department, Rabin Medical Center, Israel Abid Assali Cardiology Department, Rabin Medical Center, Israel Gideon Shafir Radiology Department, Rabin Medical Center, Israel Hana Vaknin-Assa Cardiology Department, Rabin Medical Center, Israel Israel Barbash Cardiology, Sheba Medical Center, Israel Orly Goitein Radiology Department, Sheba Medical Center, Israel Ran Kornowski Cardiology Department, Rabin Medical Center, Israel Ehud Schwammenthal Cardiology, Sheba Medical Center, Israel

Background: In patients with pathologic left ventricular hypertrophy (LVH) a mismatch between increased left ventricular mass (LVM) and blood supply may reduce coronary flow reserve. Assessing this pathophysiology typically requires complex or invasive methods.

Objectives: We investigated whether the ratio of epicardial coronary blood volume (CBV) to LVM, determined by computed tomography (CT), permits a quantitative characterization of pathological LVH.

Methods: Three hundred-six subjects with angiographically normal coronary arteries underwent CT; 73 patients with systemic hypertension (SH), 103 with aortic sternosis (AS), 55 with hypertrophic cardiomyopathy (HCM), and 75 healthy volunteers. The entire epicardial coronary tree was automatically detected to calculate CBV, LVM was calculated, and the CBV/LVM ratio was compared between normal subjects, patients with SH, AS and HCM.
Results: CBV index increased gradually from normal subjects to patients with SH, AS, and HCM (2.4 ± 0.4 ml/m², 2.7 ± 0.6 cc/m², 3.2 ± 1.1 ml/m², 3.5 ± 1.0 ml/m²; respectively, P < 0.001) in parallel to an increasing LVM index (56 ± 9 g/m², 71 ± 15 g/m², 89 ± 19 g/m², 121 ± 39 g/m²; respectively, P < 0.001). However, the CBV/LVM ratio gradually decreased from normal subjects to patients with SH, AS, and HCM (0.042 ± 0.01 ml/g, 0.039 ± 0.01 mg/ml, 0.035 ± 0.01 mg/ml, 0.030 ± 0.01 mg/ml; respectively, P < 0.001).

Conclusions: Contrast CT demonstrates that the increase in CBV observed with increasing LVM is insufficient to maintain a normal CBV/LVM ratio in pathologic LVH. Proper clinical characterization of LVH may therefore require not only quantification of muscle mass, but also of its vascular supply, and the ratio of both.