Prediction of Serious Adverse Events of Patients with Hypertrophic Cardiomyopathy by Magnetic Resonance.

Although it is well known that patients with hypertrophic cardiomyopathy (HCM) have serious adverse events, such as life-threatening arrhythmia and heart failure, the prediction of such evens is still difficult. Recently, it has been reported that one of the causes of these serious adverse events is microvascular dysfunction, which can be noninvasively evaluated by employing cardiac magnetic resonance (CMR) imaging.We analyzed 32 consecutive HCM patients via CMR imaging and myocardial scintigraphy and divided them into two groups: ventricular tachycardia (VT) group and non-VT group. Myocardial perfusion studies were conducted quantitatively using the QMass® software, and each slice image was divided into six segments. The time-intensity curve derived from the perfusion image by CMR imaging was evaluated, and the time to 50% of the peak intensity (time 50% max) was automatically calculated for each segment.Although no difference was observed in various parameters of myocardial scintigraphy between the two groups, the VT group exhibited a higher mean of time 50% max and wider standard deviation (SD) of time 50% max in each segment than the non-VT group. The cutoff values were obtained by the receiver operating characteristic curves derived from the mean of time 50% max and SD of time 50% max. The two groups divided by the cutoff values exhibited significant differences in the occurrence of serious adverse events.CMR imaging may be useful for predicting serious adverse events of patients with HCM.

Myocardial flow reserve derived by dynamic perfusion single-photon emission computed tomography reflects the severity of coronary atherosclerosis.

A novel single-photon emission computed tomography (SPECT) camera was developed to evaluate dynamic myocardial perfusion flow. However, it is unclear whether myocardial flow reserve (MFR) derived by dynamic perfusion SPECT using the novel SPECT camera (D-SPECT) reflects the severity of coronary atherosclerosis. In the present study, we therefore examined the relationship between MFR using D-SPECT and severity of coronary lesions. The study population comprised 40 patients who underwent both a myocardial dynamic perfusion SPECT study and invasive coronary angiography. The severity of coronary atherosclerosis was evaluated using the Gensini score. All patients underwent a rest/stress SPECT imaging protocol using Tc-99m-sestamibi, and dynamic acquisition was performed. Stress and rest flow was evaluated, and the global and regional MFR was calculated. Global MFR showed a significant negative correlation with Gensini score (r = - 0.345, p = 0.037). Multiple linear regression analysis showed that only global MFR was independently related to Gensini score (p = 0.018). Regional MFR was significantly lower in regions with 90% ≤ stenotic lesions compared with regions with < 90% stenotic lesions (p = 0.009). Global MFR derived by dynamic perfusion SPECT using D-SPECT reflects the severity of coronary atherosclerosis. Further, regional MFR is modulated by severe coronary artery stenotic lesions.

High Signal Intensity on T2-Weighted Cardiovascular Magnetic Resonance Imaging Predicts Life-Threatening Arrhythmic Events in Hypertrophic Cardiomyopathy Patients.

BACKGROUND: The prognostic value of high signal intensity on T2-weighted cardiovascular magnetic resonance imaging (T2 high signal) in hypertrophic cardiomyopathy (HCM) patients in a single-center cohort was investigated.Methods and Results:A total of 237 HCM patients (median age, 62 years; 143 male) underwent T2-weighted, cine and late gadolinium enhancement (LGE) imaging, and were followed (median duration, 3.4 years) for life-threatening arrhythmic events. The clinical and magnetic resonance imaging characteristics were extracted, and predictors of life-threatening arrhythmic events were assessed on multivariate analysis. LGE was present in 180 patients (75.9%). Median LGE score was 3 in a left ventricle 17-segment model. T2 high signal was present in 49 patients (20.7%). The annual events rate was significantly higher in patients with extensive LGE (score ≥4) than in those without (3.0%/year vs. 0.5%/year, P=0.011). On multivariate analysis, extensive LGE (hazard ratio, 5.650; 95% CI: 1.263-25.000, P=0.024) as an independent predictor for life-threatening arrhythmic events. In patients with extensive LGE, the annual events rate was significantly higher in patients with T2 high signal than in those without (5.8%/year vs. 0.9%/year, P=0.008). CONCLUSIONS: Extensive LGE was an independent predictor of life-threatening arrhythmic events in HCM patients. Furthermore, T2 high signal is useful for the risk stratification of serious arrhythmic events in patients with extensive LGE.

Prognostic value of cardiovascular magnetic resonance imaging for life-threatening arrhythmia detected by implantable cardioverter-defibrillator in Japanese patients with hypertrophic cardiomyopathy.

Implantable cardioverter-defibrillator (ICD) is effective to prevent sudden death in HCM patients. We reviewed ICD records to analyze the relation between life-threatening arrhythmia and late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) in Japanese hypertrophic cardiomyopathy (HCM) patients. In 102 consecutive patients (median age 63 years, 63 males) implanted with an ICD after CMR with gadolinium enhancement (median follow-up 2.8 years), the outcome of life-threatening arrhythmic events (appropriate ICD interventions for ventricular tachycardia or ventricular fibrillation) was examined. Appropriate interventions rate were 10.3% per year for secondary prevention and 7.4% per year for primary prevention. The annualized ICD-related complication rate was 3.7%. 43/91 patients (47%) implanted ICD for primary prevention had maximum wall thickness ≥20 mm plus LGE in ≥4 of 17 left ventricular segments (cut-off value obtained from ROC curve); the appropriate ICD intervention rate was significantly higher in this group than in other patients group (annualized event rate, 11.1 vs. 4.6%; log-rank P = 0.038). A combination of myocardial hypertrophy and LGE is a useful outcome predictive factor for life-threatening ventricular arrhythmia in Japanese HCM patients.

Planimetry of the Orifice Area in Aortic Valve Stenosis Using Phase-Contrast Cardiac Magnetic Resonance Imaging.

Manual planimetry is a well-established method using transesophageal echocardiography (TEE) to assess the severity of aortic stenosis (AS). TEE, however, is a less than optimal approach in patients with calcified valves. Even when using cine-cardiac magnetic resonance (CMR), it is often difficult to evaluate the true border of the aortic orifice because of jet turbulence. With phase-contrast sequences of CMR, high flow signals at the aortic orifice can be clearly visualized, even in cases with severe calcification and jet turbulence. Therefore, the aims of the present study were to compare the utility of CMR using phase-contrast imaging with TEE and cine-CMR for the performance of planimetry of the aortic valve. The study cohort consisted of 30 consecutive patients with moderate or severe aortic valve stenosis documented by TEE who had undergone phase-contrast and cine-CMR for the evaluation of AS. Manual planimetry of the area of high flow signal was traced over the phase-contrast images at systolic peak, when the aortic valve is maximally opened. The results showed that the aortic valvular area (AVA) value derived from TEE correlated better with phase-contrast planimetry (r2 = 0.84, P < 0.05) than cine-mode planimetry (r2 = 0.57, P < 0.05). Bland-Altman plots indicated that the variation of measuring AVA was greater using the cine-mode method than the phase-contrast method. In conclusion, phase-contrast CMR offers a tool for evaluating the severity of aortic valve stenosis noninvasively. Phase-contrast CMR has the potential to become a routine clinical option as an alternative to TEE, at least in selected cases.

Clinicopathological features of bi-ventricular cardiac intimal sarcoma-Report of an autopsy case.

We present the clinicopathological characteristics of primary cardiac intimal sarcoma which was widely spread throughout bi-ventricles. The patient had a wide range of clinical manifestations starting with left-sided heart failure then finally developing refractory right-sided heart failure during 44 months of follow-up. .

Computed tomography imaging to quantify the area of the endocardial subvalvular apparatus in hypertrophic cardiomyopathy - Relationship to outflow tract obstruction and symptoms.

BACKGROUND: Abnormalities of the endocardial subvalvular apparatus (SVA), which includes the papillary muscles directly attached to the mitral leaflet and left ventricular apical-basal muscle bundles, are occasionally identified in hypertrophic cardiomyopathy (HCM). Their associations with left ventricular outflow tract (LVOT) obstruction are unknown. METHODS: We retrospectively reviewed cardiac computed tomography image data sets of 107 consecutive patients with HCM [56 obstructive (HOCM) and 51 non-obstructive (HNOCM)] as well as 53 controls. We evaluated anomalies of the SVA, measured the cross-sectional area of the SVA at the level of the LVOT, and subsequently assessed its correlation with the LVOT pressure gradient with and without medication. RESULTS: The area of the SVA was greater in HOCM than in HNOCM patients and in the control group (2.5 ± 1.3 cm(2), 1.4 ± 0.8 cm(2), and 0.9 ± 0.6 cm(2), respectively; p < 0.0001). Anomalies in the SVA were more often observed in the HOCM group than in the HNOCM patients and controls (abnormal papillary muscles, 14%, 8%, and 0%, respectively; P = 0.010; LV apical-basal muscle bundles, 73%, 65%, and 45%, respectively; P = 0.0094). Among HOCM patients, logistic regression analysis demonstrated that an SVA area of 2.2 cm(2) was an independent risk factor of residual severe LVOT obstruction (≥50 mmHg) after medication (odds ratio, 10.1; 95% confidence interval, 2.05-49.80). CONCLUSION: An increased area of the endocardial subvalvular apparatus could be an independent risk factor for clinically relevant LVOT obstruction refractory to medication.

Extent of Late Gadolinium Enhancement on Cardiac Magnetic Resonance Imaging in Japanese Hypertrophic Cardiomyopathy Patients.

BACKGROUND: In addition to the presence of late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR), the extent of LGE is considered clinically important in hypertrophic cardiomyopathy (HCM). We evaluated the extent of LGE on CMR in a large series of Japanese HCM patients. METHODS AND RESULTS: CMR was performed in 317 HCM patients (147 male). The extent of LGE was scored as the sum of LGE-positive segments in a left ventricle (LV) 17-segment model. LGE was present in 246 patients (77.6%). LGE was detected in 3.5±3.1 segments on average. When the patients were divided according to maximum wall thickness (mild, <20 mm; moderate, 20-29 mm; severe, ≥30 mm), median LGE score increased as wall thickness increased (mild, 2 vs. moderate, 4 vs. severe, 5; P=0.000). When the patients were divided according to ejection fraction (EF) (reduced, <50%; low-normal, 50-65%; normal, >65%), median LGE score increased as EF decreased (reduced, 7 vs. low-normal, 4 vs. normal, 2; P=0.000). On multivariate analysis, reduced EF (OR, 0.947, P=0.015), pressure gradient <30 mmHg (OR, 0.359, P=0.000) and increased maximum wall thickness (OR, 1.236, P=0.000) were independent factors associated with extensive LGE. CONCLUSIONS: Progression of LGE was related to increased wall thickness, decreased contractility, and reduced intraventricular pressure gradient.

A preliminary feasibility study of simultaneous dual-isotope imaging with a solid-state dedicated cardiac camera for evaluating myocardial perfusion and fatty acid metabolism.

Simultaneous dual-isotope SPECT imaging with 201Tl and (123)I-ß-methyl-p-iodophenylpentadecanoic acid (BMIPP) is used to study the perfusion-metabolism mismatch. It predicts post-ischemic functional recovery by detecting stunned myocardium. On the other hand, (99m)Tc-MIBI is another radioisotope widely used in myocardial perfusion imaging because of its better image quality and lower radiation exposure than 201Tl. However, since the photopeak energies of (99m)Tc and (123)I are very similar, crosstalk hampers the simultaneous use of these two radioisotopes. To overcome this problem, we conducted simultaneous dual-isotope imaging study using the D-SPECT scanner (Spectrum-Dynamics, Israel) which has a novel detector design and excellent energy resolution. We first conducted a basic experiment using cardiac phantom to simulate the condition of normal perfusion and impaired fatty acid metabolism. Subsequently, we prospectively recruited 30 consecutive patients who underwent successful percutaneous coronary intervention for acute myocardial infarction, and performed (99m)Tc-MIBI/(123)I-BMIPP dual-isotope imaging within 5 days after reperfusion. Images were interpreted by two experienced cardiovascular radiologists to identify the infarcted and stunned areas based on the coronary artery territories. As a result, cardiac phantom experiment revealed no significant crosstalk between (99m)Tc and (123)I. In the subsequent clinical study, (99m)Tc-MIBI/(123)I-BMIPP dual-isotope imaging in all participant yielded excellent image quality and detected infarcted and stunned areas correctly when compared with coronary angiographic findings. Furthermore, we were able to reduce radiation exposure to significantly approximately one-eighth. In conclusion, we successfully demonstrated the practical application of simultaneous assessment of myocardial perfusion and fatty acid metabolism by (99m)Tc-MIBI and (123)I-BMIPP using a D-SPECT cardiac scanner. Compared with conventional (201)TlCl/(123)I-BMIPP dual-isotope imaging, the use of (99m)Tc-MIBI instead of (201)TlCl improves image quality as well as lowers radiation exposure.

Non-invasive diagnosis of coronary artery disease by 123I-BMIPP/201TlCl dual myocardial SPECT in patients with heart failure.

BACKGROUND/OBJECTIVES: Detecting the presence of coronary artery disease (CAD) is critically important in managing patients with heart failure of uncertain cause. The recently introduced 123I-BMIPP/201TlCl dual myocardial single-photon emission computed tomography (dual SPECT) is potentially a non-invasive diagnostic tool in detecting ischemic heart disease. The aim of our study is to evaluate the efficacy of detecting CAD by dual SPECT in patients with heart failure. METHODS: We studied 501 consecutive patients (366 males, mean age 68±12 years) who were admitted because of heart failure between January 2005 and April 2009. In all patients, the dual SPECT was performed in clinically stabilized states, followed by coronary angiography within 1 week. The polar map of the SPECT image was divided into 17 segments, each scored on a scale of 0-4 based on segmental percent uptake. The mismatch score was defined as the difference between 123I-BMIPP defect score and 201TlCI defect score. The uptake of 201TlCl and 123I-BMIPP was analyzed quantitatively using the Heart Score View software. RESULTS: The 201TlCI defect score and mismatch score were significantly higher in CAD patients than in non-CAD patients. The receiver operating characteristic (ROC) curve revealed that the mismatch score was a significantly more effective marker in detecting the presence of CAD than 201TlCl defect score (area under the curve: 0.84 versus 0.73, p<0.05). Using the mismatch score, the sensitivity and specificity of dual SPECT in detecting CAD were 84% and 83%, respectively. CONCLUSION: Dual SPECT is a useful non-invasive procedure for the detection of CAD in patients with heart failure.

Prognostic value of late gadolinium enhancement on cardiac magnetic resonance imaging in Japanese hypertrophic cardiomyopathy patients.

BACKGROUND: The prognostic value of late gadolinium enhancement (LGE) on contrast-enhanced cardiovascular magnetic resonance (CMR) in Japanese hypertrophic cardiomyopathy (HCM) patients in a large, single-center cohort was investigated. METHODS AND RESULTS: A total of 345 HCM patients (mean age, 59±17 years; 214 male) underwent CMR with gadolinium enhancement, and were followed (mean duration, 21.8 months) for cardiovascular events. Patients were divided into event-positive and event-negative groups. The clinical and CMR characteristics were compared between the 2 groups, and predictors of cardiovascular events assessed on multivariate analysis. LGE was positive in 252 patients (73%). The annual cardiovascular events rate was significantly higher in patients with LGE than in those without (6.2%/year vs. 0.6%/year, P=0.003). On multivariate analysis, LGE (hazard ratio [HR], 7.436; 95% confidence interval [CI]: 1.001-55.228, P=0.050), increased myocardial mass index (HR, 1.013; 95% CI: 1.002-1.023, P=0.018), reduced left ventricular ejection fraction (HR, 0.965; 95% CI: 0.945-0.985, P=0.001), and atrial fibrillation (HR, 2.257; 95% CI: 1.024-4.976, P=0.043) were significantly associated with cardiovascular events. CONCLUSIONS: The presence of LGE, increased myocardial mass index, reduced left ventricular ejection fraction and atrial fibrillation were independent predictors of adverse prognosis in Japanese HCM patients.

High signal intensity on T2-weighted cardiac magnetic resonance imaging correlates with the ventricular tachyarrhythmia in hypertrophic cardiomyopathy.

Late gadolinium enhancement (LGE) with cardiac magnetic resonance (CMR) can predict ventricular arrhythmia and poor prognosis in hypertrophic cardiomyopathy (HCM) patients. Although myocardial T2-high signal has been reported to appear within LGE in those patients, its clinical significance remains unclear. We investigated the relationship between the T2-high signal and nonsustained ventricular tachycardia (NSVT) in HCM patients. Eighty-one HCM patients who underwent Holter ECG and CMR including T2-weighted and LGE imaging were retrospectively recruited. They were divided into NSVT-positive and NSVT-negative groups. We compared the clinical and CMR characteristics between both of the groups, and assessed predictors of NSVT with multivariate analysis. Myocardial T2-high signal was observed in 15/81 (18.5 %) patients. Each T2-high signal was localized within LGE. Significantly in the NSVT-positive group, the prevalence of atrial fibrillation [5/17 (29.4 %) vs. 2/64 (3.1 %), p = 0.0006] and T2-high signal [9/17 (52.9 %) vs. 6/64 (9.4 %), p < 0.0001] and the left ventricular (LV) end-systolic volume index (32.2 ± 15.9 ml/m(2) vs. 23.3 ± 14.9 ml/m(2), p = 0.034) and the number of segments with LGE (5.8 ± 3.3 vs. 2.7 ± 2.7, p < 0.0001) was increased, and the LV ejection fraction (54.8 ± 10.9 % vs. 65.1 ± 10.6 %, p = 0.0007) was decreased, compared to the NSVT-negative group. On multivariate analysis, the presence of atrial fibrillation (OR 29.49, p = 0.0025) and DM (OR 7.36, p = 0.0455) and T2-high signal (OR 14.96, p = 0.0014) and reduced LV ejection fraction (OR 0.93, p = 0.0222) were significantly associated with NSVT. The presence of myocardial T2-high signal is a significant independent predictor of NSVT in HCM patients.

Significance of performing 123I-metaiodobenzylguanidine myocardial scintigraphy at different times for the long-term prediction of cardiac events in patients with dilated cardiomyopathy.

OBJECTIVES: Although it has been reported that (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is useful for assessing the prognosis of dilated cardiomyopathy (DCM), there have been no reports regarding how interval MIBG imaging should be performed during follow-up. We investigated the significance of performing MIBG at different times for the long-term prediction of cardiac events in DCM patients. METHODS: The participants were 36 DCM patients who did not sustain cardiac events for 2 years after beta-blocker induction. MIBG was performed 6 months and 2 years after beta-blocker induction and the images analyzed to obtain the extent score, severity score (SEV), and the washout rate. Echocardiography was performed at the same time. RESULTS: Eight patients experienced a cardiac event during follow-up (cardiac death: two patients; heart failure requiring hospitalization: six patients). Although no significant difference was found in any MIBG parameters or left ventricular ejection fraction between patients who experienced a cardiac event and those who did not after 6 months, early extent score, early SEV, delayed SEV, and washout rate were found to be significantly higher for patients who experienced a cardiac event after 2 years. In multivariate analysis using Cox proportional hazard model, none of the MIBG parameters or left ventricular ejection fraction after 6 months was identified as a predictor of cardiac events. However, delayed SEV after 2 years (hazard ratio 1.067, P = 0.0435) was a significant predictor of cardiac events. CONCLUSION: The study suggested that performing MIBG at least once every 2 years allows long-term prediction of cardiac events in the follow-up of DCM patients.