ST-segment category at acute presentation is associated with the time course of coronary artery disease progression in patients with acute coronary syndromes.

BACKGROUND: Several studies have shown higher early mortality for ST-segment elevation acute coronary syndrome (STEACS), but late mortality remains consistently higher for non-ST-segment elevation acute coronary syndrome (NSTEACS). We hypothesized that ST-segment category at acute presentation is associated with the time course of coronary artery disease progression (CP) of nonculprit lesions in patients with acute coronary syndrome (ACS). METHODS: A total of 226 patients (182 men, age 65 ± 10 years) with STEACS (n = 95) or NSTEACS (n = 131) who underwent percutaneous coronary intervention (PCI) during initial hospitalization were studied. All patients underwent serial coronary angiograms (CAGs) performed immediately before PCI and at 7 ± 3 months and 60 ± 10 months after presentation. CP was defined as an increase in stenosis severity >15% of a nonculprit lesion between 2 serial CAGs. RESULTS: The rate of CP between the first and second CAGs did not differ by ST-segment category at acute presentation. Compared to STEACS, NSTEACS had a higher rate of CP between the second and final CAGs (27.4 vs. 42.7%, P = 0.018). Multivariate analysis showed that the independent predictors of CP between the second and final CAGs were NSTEACS (odds ratio 2.709, P = 0.003), estimated glomerular filtration rate <60 ml/min/1.73 m2 (odds ratio 2.447, P = 0.015), and diabetes mellitus (odds ratio 2.135, P = 0.021). CONCLUSIONS: Irrespective of conventional risk factors and angiographic findings, ST-segment category at initial presentation is associated with the persistency of widespread coronary disease activity following presentation in ACS patients undergoing PCI. This may partly explain the time-dependent differences in outcomes of patients with STEACS and NSTEACS.

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.

Prediction of functional recovery after percutaneous coronary revascularization for chronic total occlusion using late gadolinium enhanced magnetic resonance imaging.

BACKGROUND: Limited data are available regarding the prediction for functional recovery using late gadolinium enhanced magnetic resonance imaging (LGE MRI) after coronary revascularization for chronic total occlusion (CTO PCI). METHODS: We studied 59 patients (mean age, 66±11 years) who underwent successful CTO PCI. Two-dimensional echocardiography and strain measurements were performed before and 8±2 months after CTO PCI. The findings of segmental assessment were compared with the extent of LGE MRI using a 16-segment model. RESULTS: From baseline to follow-up, ejection fraction (54.2±12.1% to 56.1±10.6%, p=0.010), global longitudinal strain (LS) (-15.1±5.1 to -16.7±5.1, p<0.001), global circumferential strain (CS) (-14.0±4.9 to -15.9±4.9, p<0.001), and wall motion score (WMS) index (1.45±0.53 to 1.33±0.39, p=0.014) significantly improved. In the territory of the CTO vessel, LS and CS significantly improved in segments of LGE ≤50%, but not in segments of LGE >50%. However, WMS improved only in segments of LGE 1-25%. At baseline and at follow-up, CS allowed better discrimination of segments of LGE >50% than WMS [at baseline; area under the curve (AUC) 0.79 vs. 0.68, respectively, p=0.001: at follow-up; AUC 0.84 vs. 0.69, respectively, p<0.001). Discriminatory ability of LS for segments of LGE >50% significantly improved from baseline to follow-up (AUC 0.73 vs. 0.83, p<0.001). CONCLUSIONS: The cut-off value of the extent of LGE MRI is 50% to detect segments that will functionally recover after CTO PCI. Change in LS was more sensitive for removal of ischemia by CTO PCI, indicating the utility of LS to monitor the therapeutic effects of CTO recanalization.

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.

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.

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.

A myocardial perfusion imaging system using a multifocal collimator for detecting coronary artery disease: validation with invasive coronary angiography.

OBJECTIVE: Myocardial perfusion imaging (MPI) systems using a multifocal collimator can reduce scan time substantially compared with conventional MPI systems. In this study, we evaluated the diagnostic accuracy of multifocal collimator SPECT/CT in coronary artery disease (CAD) detection by comparing it with coronary artery angiography (CAG). METHODS: We retrospectively analyzed 50 consecutive patients who had undergone CAG and stress (201)Tl MPI multifocal collimator SPECT/CT within a 3-month period. A summed difference score (SDS) was calculated for each vascular territory from the MPI images. On CAG, a stenotic coronary artery was defined as one with luminal narrowing of ≥75 % with quantitative coronary angiography software. RESULTS: We analyzed the diagnostic accuracy of coronary artery stenosis detection using the definition that a coronary artery territory was ischemic when the SDS per vessel was ≥2. We generated receiver operating characteristic (ROC) curves to evaluate the usefulness of SDS per vascular territory to find coronary artery stenoses. The area under the ROC curve was 0.86 and cut-off value was 2. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy to detect stenoses were 85, 83, 66, 94 and 84 %, respectively. CONCLUSIONS: We confirmed the high accuracy of imaging with multifocal collimator SPECT/CT for detection of angiographically significant CAD.

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.