Diagnostic capabilities of cardiac computed tomography in the preoperative diagnosis of hypertrophic cardiomyopathy

BACKGROUND: A comprehensive approach to studying hypertrophic cardiomyopathy with diagnostic equipment and the latest scanning methods will ensure quality control and effective treatment of patients with this condition. The implementation of innovative technologies and computer calculation using next-generation scanners may become relevant and promising in studying various phenotypes of left ventricular remodeling in combination with abnormalities of the chordopapillary apparatus of the mitral valve and myocardial structure. AIM: To examine the diagnostic capabilities of computed tomography in the preoperative examination of various hypertrophic cardiomyopathy phenotypes. MATERIALS AND METHODS: The retrospective data analysis included 47 patients with hypertrophic cardiomyopathy (mean age, 52±7 full years) before surgical correction. computed tomography was performed using our protocol with automatic bolus tracking in the left atrium with a 90 HU threshold and biphasic contrast injection to assess the heart chambers and coronary arteries anatomy and mitral valve morphology. Moreover, to assess myocardial structure remodeling, iodine dual-energy computed tomography maps obtained with delayed contrast enhancement were analyzed. All patients with hypertrophic cardiomyopathy were classified by morphological types. The anatomy of chordopapillary apparatus was evaluated in each case. RESULTS: This study demonstrated variability in hypertrophic cardiomyopathy phenotypes, which were conventionally divided into five morphological categories, but not restricted by them. Among the patients, 26 (55%) had diffuse septum hypertrophic cardiomyopathy, 5 (11%) had midventricular hypertrophic cardiomyopathy, 2 (4%) had midventricular obstruction and apical aneurysm, 8 (18%) had focal basal septum hypertrophic cardiomyopathy, 4 (8%) had concentric hypertrophic cardiomyopathy, and the remaining 4 (8%) had apical hypertrophic cardiomyopathy. Most patients were diagnosed with chordopapillary abnormalities of the mitral valve, categorized by papillary muscle number and position, and the ratio of chords to muscles. In 10 (21%) patients, data on the myocardial bridge of a coronary artery were obtained, whereas 3 (14%) of them had dynamic stenosis. All patients had focal iodine uptake on dual-energy computed tomography maps. An extracellular volume increase was observed in 10 out of 13 (76%) patients. As shown by dual-energy computed tomography, the mean extracellular volume of the left ventricular myocardium was 30.58% (95% confidence interval, 27–34%). CONCLUSION: Our scanning protocols developed with computed tomography scanners of various generations enable to evaluate the specific morphological patterns of hypertrophic cardiomyopathy in a single study and provide a detailed interpretation of the geometry of cardiac valves and chambers, left ventricular function, state of the coronary bed, and structural changes of the left ventricular myocardium.