Incremental prognostic value of the SYNTAX score to late gadolinium-enhanced magnetic resonance images for patients with stable coronary artery disease.

The prognostic significance of the SYNTAX (Synergy between PCI with Taxus and cardiac surgery) score has recently been demonstrated in patients with stable multivessel or left main coronary artery disease (CAD). The present study determines whether adding the SYNTAX score to Framingham risk score (FRS), left ventricular ejection fraction (LVEF) and presence of myocardial infarction (MI) by late gadolinium enhancement (LGE) magnetic resonance imaging can improve the risk stratification in patients with stable CAD. We calculated the SYNTAX score in 161 patients with stable CAD (mean age: 66 ± 10 years old). During a mean follow-up of 2.3 years, 56 (35 %) of 161 patients developed cardiovascular events defined as cardiovascular death, non-fatal MI, cerebral infarction, unstable angina pectoris, hospitalization due to heart failure and revascularization. Multivariate Cox regression analysis selected triglycerides [hazard ratio (HR): 1.005 (95 % confidence interval (CI): 1.001-1.008), p < 0.008], presence of LGE [HR: 6.329 (95 % CI: 2.662-15.05), p < 0.001] and the SYNTAX score [HR: 1.085 (95 % CI: 1.044-1.127), p < 0.001] as risk factors for future cardiovascular events. Adding the SYNTAX score to FRS, EF and LGE significantly improved the net reclassification index (NRI) [40.4 % (95 % CI: 18.1-54.8 %), p < 0.05] with an increase in C-statistics of 0.089 (from 0.707 to 0.796). An increase in C-statistics and significant improvement of NRI showed that adding the SYNTAX score to the FRS, LVEF and LGE incrementally improved risk stratification in patient with stable CAD.

Prognostic value of cardiovascular magnetic resonance derived right ventricular function in patients with interstitial lung disease.

BACKGROUND: Cardiovascular magnetic resonance (CMR) provides non-invasive and more accurate assessment of right ventricular (RV) function in comparison to echocardiography. Recent study demonstrated that assessment of RV function by echocardiography was an independent predictor for mortality in patients with interstitial lung disease (ILD). The purpose of this study was to determine the prognostic significance of CMR derived RV ejection fraction (RVEF) in ILD patients. METHODS: We enrolled 76 patients with ILD and 24 controls in the current study. By using 1.5 T CMR scanner equipped with 32 channel cardiac coils, we performed steady-state free precession cine CMR to assess the RVEF. RV systolic dysfunction (RVSD) was defined as RVEF ≤45.0% calculated by long axis slices. Pulmonary hypertension (PH) was defined as mean pulmonary artery pressure (mPAP) of more than 25 mmHg at rest in the setting of pulmonary capillary wedge pressure ≤15 mmHg. RESULTS: The median RVEF was 59.2% in controls (n = 24), 53.8% in ILD patients without PH (n = 42) and 43.1% in ILD patients with PH (n = 13) (p < 0.001 by one-way ANOVA). During a mean follow-up of 386 days, 18 patients with RVSD had 11 severe events (3 deaths, 3 right heart failure, 3 exacerbation of dyspnea requiring oxygen, 2 pneumonia requiring hospitalization). In contrast, only 2 exacerbation of dyspnea requiring oxygen were observed in 58 patients without RVSD. Multivariate Cox regression analysis showed that RVEF independently predicted future events, after adjusting for age, sex and RVFAC by echocardiography (hazard ratio: 0.889, 95% confidence interval: 0.809-0.976, p = 0.014). CONCLUSIONS: The current study demonstrated that RVSD in ILD patients can be clearly detected by cine CMR. Importantly, low prevalence of PH (17%) indicated that population included many mild ILD patients. CMR derived RVEF might be useful for the risk stratification and clinical management of ILD patients.

Low-normal lung volume correlates with pulmonary hypertension in fibrotic idiopathic interstitial pneumonia: computer-aided 3D quantitative analysis of chest CT.

OBJECTIVE: We investigated whether the lung volume determined on CT, especially the volume of the normal lung, is correlated with mean pulmonary artery pressure (PAP) in patients with chronic fibrosing idiopathic interstitial pneumonia (IIP). MATERIALS AND METHODS: The subjects were 40 patients with IIP who underwent right heart catheterization (RHC) and chest CT. Thirty-three patients (82.5%) were smokers or former smokers. Using a computer-aided system, the lungs in the 3D CT images were automatically categorized pixel-by-pixel with gaussian histogramnormalized correlations, and the relative volume of each lesion to the CT lung volume was calculated as "normal(%)," "ground-glass opacities(%)," "consolidation(%)," "emphysema(%)," and "fibrosis(%)." The relationship between each "volume(%)" and pulmonary hypertension was evaluated using logistic regression analysis. ROC curves were constructed to assess the predictive value of these CT-based volumes in the identification of pulmonary hypertension. RESULTS: Sixteen patients had pulmonary hypertension at rest (mean PAP > 25 mm Hg on RHC). Emphysema constituted more than 10% of the CT lung volume in 13 patients. On multivariate analysis of each volume(%), normal(%) was significant for detecting pulmonary hypertension (odds ratio, 0.92; 95% CI, 0.86-0.96; p = 0.02). On ROC analysis, the AUC of normal(%) was 0.849 (0.731-0.967). CONCLUSION: The relative CT volume of any single lesion was of limited value in predicting pulmonary hypertension in patients with pulmonary fibrosis and emphysema. In these patients, normal(%), measured by a 3D computer-aided system, was correlated with pulmonary hypertension measured by RHC.

Relationship between coronary flow reserve evaluated by phase-contrast cine cardiovascular magnetic resonance and serum eicosapentaenoic acid.

BACKGROUND: Long-term intake of long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs), especially eicosapentaenoic acid (EPA) is associated with a low risk for cardiovascular disease. Phase-contrast cine cardiovascular magnetic resonance (PC cine CMR) can assess coronary flow reserve (CFR). The present study investigates the relationship between CFR evaluated by PC cine CMR and the serum EPA. METHODS: We studied 127 patients (male, 116 (91%); mean age, 72.2 ± 7.4 years) with known or suspected coronary artery disease (CAD). X-ray coronary angiography revealed no significant coronary arterial stenoses (defined as luminal diameter reduction ≥ 50% on quantitative coronary angiogram (QCA) analysis) in all study participants. Breath-hold PC cine CMR images of the coronary sinus (CS) were acquired to assess blood flow of the CS both at rest and during adenosine triphosphate (ATP) infusion. We calculated CFR as CS blood flow during ATP infusion divided by that at rest. Patients were allocated to groups according to whether they had high (n = 64, EPA ≥ 75.8 µg/mL) or low (n = 63, EPA < 75.8 µg/mL) median serum EPA. RESULTS: CFR was significantly lower in the low, than in the high EPA group (2.54 ± 1.00 vs. 2.91 ± 0.98, p = 0.038). Serum EPA positively correlated with CFR (R = 0.35, p < 0.001). We defined preserved CFR as > 2.5, which is the previously reported lower limit of normal flow reserve without obstructive CAD. Multivariate analysis revealed that EPA is an independent predictor of CFR > 2.5 (odds ratio, 1.01; 95% confidence interval, 1.00 - 1.02, p = 0.008). CONCLUSIONS: The serum EPA is significantly correlated with CFR in CAD patients without significant coronary artery stenosis.

Higher CHADS2 score is associated with impaired coronary flow reserve: A study using phase contrast cine magnetic resonance imaging.

BACKGROUND: The presence of coronary microvascular dysfunction (CMD) is an important prognostic marker for coronary artery disease (CAD) patients. The purpose of this study was to investigate whether the CHADS2 score is associated with CMD evaluated by magnetic resonance imaging (MRI). MATERIALS AND METHODS: One hundred forty three patients with known or suspected CAD (mean age 70.3±9.5years) were enrolled. All patients did not have any significant coronary stenosis on X-ray coronary angiography (CAG) at the time of MRI acquisition. By using a 1.5T MRI scanner, breath-hold phase contrast cine MRI images of coronary sinus (CS) were obtained to assess the blood flow of CS both at rest and during adenosine triphosphate (ATP) infusion. Coronary flow reserve (CFR) was calculated as CS blood flow during ATP infusion divided by CS blood flow at rest. CMD was defined as CFR<2.5 according to a previous study. Patients were allocated to four groups based on the CHADS2 score (group1: CHADS2 score=0, group2: CHADS2 score=1; group3: CHADS2 score=2, and group4: CHADS2 score≥3). RESULTS: Mean CFR was 2.81±0.95 (77.6±32.7mL/min at rest; 208.2±86.5mL/min during ATP infusion, p<0.001). Patients with higher CHAD2 score had lower CFR. In the multiple logistic regression analysis, CHADS2 score was independently associated with CFR (odds ratio=0.61, 95% confidence interval: 0.37-0.99, p=0.049). CONCLUSIONS: Higher CHADS2 score was significantly associated with lower CFR evaluated by phase contrast cine MRI.

Inhibition of DPP-4 by alogliptin improves coronary flow reserve and left ventricular systolic function evaluated by phase contrast cine magnetic resonance imaging in patients with type 2 diabetes and coronary artery disease.

BACKGROUND: The present study determined whether dipeptidyl peptidase-4 (DPP-4) inhibition by alogliptin improves coronary flow reserve (CFR) and left ventricular election fraction (LVEF) in patients with type 2 DM and CAD. MATERIALS AND METHODS: Twenty patients with type 2 DM and known or suspected CAD were randomly allocated to receive diet therapy plus alogliptin (n=10; mean age, 73.3±6.6y) or a control group given diet therapy and glimepiride (n=10; mean age, 76.7±7.3y). Breath-hold PC cine MR images of the coronary sinus (CS) were acquired using a 1.5T MR scanner and 32 channel cardiac coils to assess blood flow of the CS at rest and during adenosine triphosphate (ATP) infusion. The CFR was calculated as CS blood flow during ATP infusion divided by that at rest. The CFR and LVEF were evaluated by MRI at baseline and at three months after starting therapy. RESULTS: Hemoglobin A1c (HbA1c) was significantly reduced in both groups (alogliptin, 7.2±0.6% to 6.6±0.5%, p=0.034; control, 6.9±0.4% to 6.4±0.3%, p=0.008). However, CFR and LVEF significantly improved only in the alogliptin group (alogliptin: CFR, 2.15±0.61 to 2.85±0.80, p=0.042; LVEF, 59.4±6.3% to 68.0±8.6%, p=0.03; control: CFR, 2.17±0.37 to 2.38±0.32, p=0.19; LVEF, 58.2±9.1 to 60.3±8.8%, p=0.61). The % increases in CFR and in LVEF positively correlated (R=0.47 by Spearman's correlation coefficient; p=0.036). CONCLUSION: The inhibition of DPP-4 by alogliptin improved CFR and LVEF evaluated by MRI in patients with type 2 DM and CAD and the improvement in CFR was associated with increased LV systolic function.

Impairment of Coronary Flow Reserve Evaluated by Phase Contrast Cine-Magnetic Resonance Imaging in Patients With Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Phase contrast (PC) cine-magnetic resonance imaging (MRI) of the coronary sinus allows for noninvasive evaluation of coronary flow reserve (CFR), which is an index of left ventricular microvascular function. The objective of this study was to investigate coronary flow reserve in patients with heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: We studied 25 patients with HFpEF (mean and SD of age: 73±7 years), 13 with hypertensive left ventricular hypertrophy (LVH) (67±10 years), and 18 controls (65±15 years). Breath-hold PC cine-MRI images of the coronary sinus were obtained to assess blood flow at rest and during ATP infusion. CFR was calculated as coronary sinus blood flow during ATP infusion divided by coronary sinus blood flow at rest. Impairment of CFR was defined as CFR <2.5 according to a previous study. The majority (76%) of HFpEF patients had decreased CFR. CFR was significantly decreased in HFpEF patients in comparison to hypertensive LVH patients and control subjects (CFR: 2.21±0.55 in HFpEF vs 3.05±0.74 in hypertensive LVH, 3.83±0.73 in controls; P<0.001 by 1-way ANOVA). According to multivariable linear regression analysis, CFR independently and significantly correlated with serum brain natriuretic peptide level (ß=-68.0; 95% CI, -116.2 to -19.7; P=0.007). CONCLUSIONS: CFR was significantly lower in patients with HFpEF than in hypertensive LVH patients and controls. These results indicated that impairment of CFR might be a pathophysiological factor for HFpEF and might be related to HFpEF disease severity.

Prognostic significance of quantitative assessment of focal myocardial fibrosis in patients with heart failure with preserved ejection fraction.

BACKGROUND: The aim of this study was to investigate the prognostic value of myocardial focal fibrosis quantified by late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) in patients with heart failure with preserved ejection fraction (HFpEF). METHODS: One-hundred eleven HFpEF patients (mean age: 70 ± 14 years, 55 (50%) female) were enrolled. We excluded patients with previous history of coronary artery disease and/or ischemic pattern of hyper enhancement on LGE MRI. Myocardial enhancement was defined using signal intensity >2SD above the mean signal intensity of a remote myocardium. Major adverse cardiovascular events were defined as cardiovascular death and heart failure requiring hospitalization. RESULTS: During a mean follow up period of 851 ± 609 days, 10 events (2 cardiovascular death, 8 hospitalization for heart failure decompensation) were observed. Area under the receiver operating characteristics curve of LGE% for the detection of future events was 0.721 (95% CI: 0.628-0.802). Multivariate Cox proportional hazard analysis showed that LGE% is an independent predictor of future events after the adjustment with prognostic 5 factors - age, diabetes mellitus, New York Heart Association classification, history of heart failure hospitalization and left ventricular ejection fraction - which were identified in the I-PRESERVE study (Irbesartan in Heart Failure with Preserved Ejection Fraction Study) (hazard ratio=7.913, 95% CI: 1.603-39.05, P=0.012). CONCLUSIONS: Larger size of LGE was significantly associated with high rate of future cardiovascular death and heart failure hospitalization, suggesting that the quantification of myocardial focal fibrosis by LGE MRI could be useful for the risk stratification in HFpEF patients.