Evaluation and implications of mitral regurgitation using cMRI in patients with hypertrophic cardiomyopathy.

OBJECTIVE: Mitral regurgitation (MR) represents an important feature in patients with hypertrophic cardiomyopathy (HCM) due to left ventricular outflow tract (LVOT) obstruction and mitral valve systolic anterior motion (SAM). Mitral valve anatomical variants associated with HCM also contribute to the severity of MR. The aim of this study is to evaluate MR severity and its correlation with different parameters in patients with HCM using cardiac magnetic resonance imaging (cMRI). PATIENTS AND METHODS: 130 patients with HCM underwent cMRI. Parameters assessed for the quantification of MR severity were mitral regurgitation volume (MRV) and mitral regurgitation fraction (MRF). cMRI was also used to characterize LV function, left atrium volume (LAV) index, filling pressures and structural abnormalities associated with HCM, all in correlation to MR. RESULTS: Patients with HCM had mild (26.9%), moderate (52.3%) or severe (20.7%) MR. Most relevant parameters related to MR severity were MRV and MRF; other parameters with strong correlation with MR were LAV index and E/E' ratio, both increasing with its severity. Patients with LVOT obstruction had more severe MR (70.3%), 79% of them due to SAM. LV ejection fraction (LVEF) increased proportionally with the severity of MR, while LV strain (LAS) was inversely correlated with it. Independent predictors for quantifying the severity of MR, after the adjustment for covariates, were MRV, MRF, SAM, LAV index and E/E'. CONCLUSIONS: cMRI can accurately assess MR in patients with HCM, especially by using novel indicators, MRV and MRF respectively, along with LAV index and E/E' ratio. Severe MR, due to SAM, is more frequent in the obstructive form of HCM (HOCM). Also, the severity of MR is significantly associated with significantly associated with MRV, MRF, LAV index and E/E' ratio.

Characterization of left atrial geometry and function in patients with hypertrophic cardiomyopathy: a cardiac magnetic resonance imaging study.

OBJECTIVE: Left atrial (LA) remodelling is an interesting pathological aspect in hypertrophic cardiomyopathy (HCM) which has not been yet fully understood. Also, a comprehensive evaluation of LA alterations in HCM is still lacking. Cardiac magnetic resonance imaging (cMRI) can precisely characterize LA function and structure. We sought to thoroughly assess LA remodelling using cMRI in patients with HCM. PATIENTS AND METHODS: We enrolled 105 patients with HCM and 105 healthy controls. LA parameters determined by cMRI comprise LA volume (LAV), total ejection fraction (LATF), total strain LA- εt, passive ejection fraction (LAPF), passive strain LA-εe, active ejection fraction (LAAF), active strain LA-εa. LA sphericity index (LASI) and LA strain were also determined. Parameters of LV systolic and diastolic functions were also assessed. RESULTS: LAV and LASI were significantly increased, while LA phasic functions were decreased in patients with HCM (p<.001). LATF was inversely correlated with LV long-axis strain (r= -0.466, p<.0001) and mass (r= -0.515, p<.0001), and as well with filling pressures, described by E/E' (r= -0.424, p<.0001). LA volumes, phasic functions and geometry were negatively associated with LV measurements, whereas a positive correlation between the LATF and LA strain (r = 0.496, p<.0001) was found. In addition, LAV was closely related to diastolic dysfunction severity (p<.0001). CONCLUSIONS: In patients with HCM, all three LA phasic functions were impaired, being directly related to LA enlargement. LASI and LA strain predicted LA reservoir function impairment.

Predictive ability of coronary computed tomography angiography parameters in patients suspected of obstructive coronary artery disease: a single-center cross-sectional study.

OBJECTIVE: Coronary computed tomography angiography (CCTA) is becoming increasingly useful for the diagnosis of coronary artery disease (CAD). Coronary calcium score (CCS), epicardial fat volume (EFV), and number of coronary plaques (NoP) add important information for the risk stratification and prognosis prediction of these patients. However, evidence about their ability to predict obstructive CAD is limited. We sought to evaluate the ability of CCTA parameters in predicting obstructive CAD. PATIENTS AND METHODS: We conducted a cross-sectional, single-center study on patients at risk to develop CAD. CAD was defined as coronary stenosis > 50% after the other one (CCS, EFV and NoP were determined by CCTA). CCS was then ranked 5 severity groups: 0, 1-99, 100-399,400-999, and ≥1000. NoPs were classified in four categories: no plaques, 1-5, 6-10 and ≥10. Logistic regression analyses were performed, and statistical analysis was considered significant if p<0.05. RESULTS: Of all 540 patients (55.8±11.1 years) who met the enrolment criteria, 98 had obstructive CAD. CCS, EFV and NoP were significantly associated with the presence of obstructive CAD (p<0.0001). The area under the receiver operating characteristics (ROC) analysis revealed significant cut-off values (p<0.0001) of CCS (70.3), EFV (40.8), NoP (4) for predicting obstructive CAD. Their association proved to have an AUC of 0.969, and a specificity of 95%. A scoring system based on regression coefficients which proved to have statistical significance for obstructive CAD as further constructed. It included EFV, CCS and left ventricular ejection fraction. This scoring system significantly predicted obstructive CAD for a cut-off value of 62.46, with a NPV of 96.3%. CONCLUSIONS: The combined use of CCS, EFV and NoPs increases the predictive ability for obstructive CAD of each parameter used alone. These could be useful for developing a novel scoring system.

Aging influences pulmonary artery flow and stiffness in healthy individuals: non-invasive assessment using cardiac MRI.

AIM: To investigate age-related changes of the pulmonary artery (PA) using cardiac magnetic resonance imaging (cMRI) in healthy subjects. MATERIALS AND METHODS: A cross-sectional observational study was conducted on apparently healthy subjects who underwent PA velocity-encoded cMRI. cMRI was used to determine PA stiffness parameters such as PA elasticity, relative area change (PA-RAC) and pulse-wave velocity (PA-PWV), and PA flow parameters by subtracting simultaneous forward flow (FF) and backward flow (BF) velocity across the PA cross-section. Data were presented in five age and sex matched groups. RESULTS: One hundred and fifty subjects (20-70 years, 75 men) met the enrolment criteria. PA elasticity and PA-RAC significantly decreased with age (p<0.001), while PA-PWV, regurgitant volume (Vreg) and backward flow volume (VBF) increased in the elderly (p<0.001). Linear regression analysis indicated that PA elasticity (r=-0.441, p<0.0001) and PA-RAC (r=-0.484, p<0.0001) were indirectly and negatively associated with advancing age, whereas PAmin (r=0.331, p<0.0001), PA-PWV (r=0.490, p<0.0001), VReg (r=0.335, p<0.0001) and VBF (r=0.349, p<0.0001) were directly associated with age. Multivariate analysis indicated that age was independently associated with Vreg and VBF, and the addition of PAmin and PA-PWV marginally increased its predictive capacity. CONCLUSION: Aging significantly increases cMRI-based PA flow and stiffness parameters. These could become relevant markers of subclinical changes of the PA geometry in healthy subjects.