Hisataka Sasao

Cardiac death prediction and impaired cardiac sympathetic innervation assessed by MIBG in patients with failing and nonfailing hearts.

BackgroundAlthough cardiac sympathetic nerve dysfunction is related to poor clinical outcome, a critical sympathetic dysfunction level for predicting cardiac death is still unclear. The current study was designed to investigate which indices derived from metaiodobenzylguanidine (MIBG) imaging have prognostic value compared with clinical and cardiac function variables, and to determine the threshold of cardiac MIBG activity for identifying patients likely to suffer cardiac death in both failing and nonfailing hearts.Methods and ResultsMyocardial I-123-MIBG activity was quantified as a heart-to-mediastinum ratio in 414 consecutive patients, 173 (42%) of whom had symptomatic heart failure. After cardiac function measurements, patients were followed up with an end-point of cardiac or noncardiac death. During a mean follow-up period of 22 months, 37 cardiac deaths occurred: 23 resulted from heart failure, 9 were sudden cardiac deaths, and 5 were fatal myocardial infarctions. Multivariate analysis using the Wald χ2 and the Cox proportional hazard model revealed that late heart-to-mediastinum ratio, the use of nitrates, early heart-to-mediastinum ratio, and left ventricular ejection fraction were independent predictors of cardiac death; late heart-to-mediastinum ratio, New York Heart Association (NYHA) class, the presence of previousmyocardial infarction, and age were independent predictors of heart failure and sudden cardiac death. Late heart-to-mediastinum ratio was the most powerful predictor of overall cardiac death among the variables. The Kaplan-Meier analysis showed that a late heart-to-mediastinum ratio of 1.74 or less, age greater than 60 years, the presence of myocardial infarction, and NYHA functional class 3 or 4 strongly indicated poor clinical outcomes. Furthermore, the more powerful incremental prognostic values were obtained by using MIBG imaging in combination with conventional clinical variables.ConclusionsImpaired cardiac sympathetic innervation assessed by MIBG activity has the greatest potential for predicting cardiac death and may be useful for identifying a threshold level for selecting patients at risk for death by heart failure, sudden cardiac death, and fatal myocardial infarction.

Technetium-99m sestamibi/tetrofosmin myocardial perfusion scanning in cardiac and noncardiac sarcoidosis

Left ventricular (LV) and right ventricular (RV) involvement in sarcoidosis must be firmly confirmed to determine patients’ prognosis. We examined whether myocardial perfusion images using technetium-99m single photon emission computed tomography (SPECT) have a diagnostic benefit in the evaluation of biventricular involvement. Sixteen patients with sarcoidosis, aged 21–78 (54 ± 12) years old, 5 males and 11 females, complicated with cardiac disease (cardiac sarcoidosis, n = 6) including tachyarrhythmias of ventricular origin (n = 5), atrioventricular block (n = 4), and congestive heart failure (NYHA ≧ II, n = 1), were enrolled in this study. Myocardial SPECT using technetium-99m sestamibi or tetrofosmin was performed and semiquantitatively scored for comparison with 25 control subjects. Perfusion abnormalities were more frequently recognized in sarcoidosis (LV 5/16, 31% and RV 14/16, 88% vs. LV 0/25, 0% and RV 8/25, 32% in controls). LV involvement had a close correlation with atrioventricular block and with congestive heart failure, and multiple sites of RV involvement correlated with ventricular tachyarrhythmia of RV origin. Total number of defect segments were highest in cardiac sarcoidosis (18/30, 60% vs. 19/60, 32% in noncardiac sarcoidosis, and 11/150, 7% in controls, p = 0.0001), and semiquantitatively evaluated total LV and RV scores (ranging from 0 to 18) were higher than those of controls (15.1 ± 1.8 vs. 11.4 ± 3.0 in noncardiac sarcoidosis, and 9.0 ± 5.0 in cardiac sarcoidosis) and exhibited a significant positive linear correlation with the RV ejection fraction (y = 19.8 + 1.83x, r = 0.786, p = 0.001). Biventricular SPECT using technetium-99m is clinically useful for the noninvasive evaluation of both ventricular involvements in sarcoidosis.

Prognostic value of the Tei index combining systolic and diastolic myocardial performance in patients with acute myocardial infarction treated by successful primary angioplasty

Cardiac systolic (left ventricular ejection fraction) and diastolic (mitral inflow velocity pattern and/or mitral deceleration time) function were reported as predictors of clinical outcome or left ventricular remodeling in patients with acute myocardial infarction (AMI). Recently, a new index (Doppler-derived index combining systolic and diastolic myocardial performance; Tei index) for combined systolic and diastolic ventricular function has been reported to be a useful and convenient method for evaluation of global ventricular function. We therefore investigated the usefulness of the Tei index by echocardiography for evaluation of infarct size and clinical outcome in patients with AMI treated by successful primary angioplasty. We analyzed 10 age-matched control subjects and 43 consecutive patients with first AMI treated by successful primary angioplasty. The Tei index of the AMI patients was significantly greater than that of the control subjects (0.630 ± 0.106 vs 0.375 ± 0.036, P ≪ 0.0001). Also, the Tei index showed a significant positive correlation with peak creatine kinase values and 99mTc-tetrofosmin scores. Moreover, multiple logistic regression analysis showed that the Tei index ≫0.70 (P = 0.0313, odds ratio = 14.14) was the only significant explanatory factor for cardiac death or developed congestive heart failure. The Tei index combining systolic and diastolic myocardial performance reflects infarct size and might be a predictor of clinical outcome in patients with AMI treated by successful primary angioplasty.

Insulin resistance functionally limits endothelium-dependent coronary vasodilation in nondiabetic patients

Insulin resistance (IR) is now considered to be a risk factor for coronary arterial atherosclerosis and is likely to be involved in a limited endothelium-dependent vasodilatory function in peripheral circulation. We investigated whether IR impairs endothelial vasodilator function in the noninfarcted coronary artery. In 14 nondiabetic patients (10 males, 66 ± 6 years) who were selected from 214 patients underwent IR evaluation by glucose clamp, a Doppler flow wire was used to measure coronary flow changes (percent volume flow index, %VFI) during intracoronary administration of papaverin (10 mg) and stepwise administration of acetylcholine (Ach; 1, 3, 10 μg/ml per minute) into the non-infarcted left circumflex coronary artery. Insulin resistance was comparatively evaluated by an euglycemic hyperinsulinemic glucose clamp (M value, mg/m2 per minute) or by a 75g-oral glucose tolerance test (120-min immunoreactive insulin; 120′ IRI, pmol/l). Eight patients (57%) were defined as having IR on the basis of results obtained by both the glucose clamp method (M values <167 mg/m2 per minute) and 120′ IRI (>384 pmol/l). There was no difference between papaverin-induced %VFI increases in IR and non-IR subjects (328% ± 43% vs. 361% ± 87%). However, IR subjects showed significantly lower Ach-induced %VFI increases in a dose-dependent manner (P < 0.05), especially when low (1 μg/ml per minute) and moderate (3 μg/ml per minute) doses of Ach were used (165% ± 18% or 248% ± 29% in non-IR subjects vs. 130% ± 20% or 183% ± 41% in IR subjects, P < 0.001, respectively). Moreover, %VFI increase at a low dose of Ach infusion significantly correlated with M values or 120′ IRI ([%VFI Ach 1 μg] = 85.9 + 0.35 [M values], r = 0.58, P = 0.038; [%VFI Ach 1 μg] = 176.8 − 0.47·[120′ IRI], r = −0.57, P = 0.035). Insulin resistance limits endothelium-dependent coronary vasodilation in association with the severity of IR in non-diabetic patients.

Coronary stent implantation in patients with a single coronary artery--a report of 3 cases.

An isolated single coronary artery is a rare congenital anomaly and a cause of cardiac ischemia, congestive heart failure, and sudden cardiac death. Reported here are 3 cases of single coronary artery with acute myocardial infarction in which coronary stenting was performed. Also reported are the coronary blood flow patterns of the right coronary artery arising from the single left coronary artery.

Comparison of Long-Term Clinical Outcomes after Drug-Eluting Stent Implantation in Patients with Coronary Artery Disease with and without Prior Cerebral Infarction.

OBJECTIVE To compare the clinical and angiographic outcomes after implantation of drug-eluting stents (DESs) in patients with coronary artery disease (CAD) with or without prior cerebral infarction. MATERIALS AND METHODS Ninety-eight consecutive patients (130 lesions) who underwent successful coronary DES implantation were prospectively classified into two groups: those with a clinical history of symptomatic cerebral infarction (cerebral infarction group, 49 patients, 69 lesions) and those without a clinical history of symptomatic cerebral infarction (noncerebral infarction group, 49 patients, 61 lesions). The primary endpoint was defined as death, nonfatal myocardial infarction, and cerebrovascular events. RESULTS The Kaplan-Meier method was used to create a primary endpoint curves to determine the time-dependent cumulative primary endpoint-free rate, which were compared using the log-rank test. The incidence of primary endpoints was higher in the cerebral infarction group than in the noncerebral infarction group (p = 0.0075). The Cox proportional hazards regression model for primary endpoint identified prior cerebral infarction (p = 0.0331, hazard ratio = 2.827) and patients with peripheral artery disease (p = 0.0271, hazard ratio = 2.757) as explanatory factors. CONCLUSION The results showed that clinical outcomes were poorer in patients with CAD who had prior cerebral infarctions than in those who did not have infarction.

Long-term follow-up after coronary stent implantation in patients with coronary artery disease.

Prospective randomized trials of coronary stenting in patients with coronary artery disease have shown a reduced incidence of cardiac events. However, little is known of the late outcome of patients treated with coronary stenting. The purpose of this study was to evaluate the rela tively long-term clinical outcomes (3 to 6 years) of patients treated with successful coronary stenting. The long-term clinical outcome was studied in 101 consecutive patients (78 males and 23 females) who had undergone successful coronary stent implantation for coronary artery disease in our hospital from October 1994 to September 1997. During a follow-up period of 48.9 ±9.5 months (range, 6-73 months), cardiac events were documented in 37 patients. The rate of survival free of cardiac events was 67% at 3 years. Multiple logistic regression analysis showed that ACC/AHA lesion type and residual percent diameter stenosis greater than 20% after stenting were the significant explanatory factors of adverse cardiac events. Long-term clinical outcome in patients with coronary artery disease treated with successful coronary stenting was influenced by the ACC/AHA lesion type of stented lesion and residual percent diameter stenosis after stent implantation.

Cardiac imaging in a patient with anomalous origin of the left coronary artery from the pulmonary artery: a case report

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is an uncommon congenital heart disease and has a high mortality rate in infancy. However, myocardial ischemia does not develop until adolescence or adulthood in about 10% of patients. Moreover, the diagnosis of ALCAPA is often difficult in cases without heart murmur or cardiac symptoms. The authors report the case of a 31-year-old man with ALCAPA. He was admitted to the hospital for evaluation of mild shortness of breath at exercise, but he had no typical chest symptoms due to myocardial ischemia or heart failure until age 31 and he had no heart murmur. Moreover, electrocardiogram did not show an old myocardial infarction or myocardial ischemia. Therefore, the authors did not suspect ALCAPA until they performed transthoracic echocardiography and exercise-stress single photon emission computed tomography (SPECT) with Tc-99m-tetrofosmin. The final diagnosis was established from the results of coronary arteriography. In the present case, a transthoracic echocardiogram showed abnormal coronary circulation, and exercise-stress SPECT revealed reversible myocardial ischemia. Transthoracic echocardiography and myocardial SPECT imaging could be a useful noninvasive tools for diagnosing the ALCAPA.

Primary stenting in nonagenarian patients with acute myocardial infarction: A report of two cases

Previous studies suggested that mortality among elderly patients with acute myocardial infarction (AMI) is higher than that of younger patients. On the other hand, previous studies also suggested that primary angioplasty for elderly patients with AMI is superior to thrombolytic therapy. However, little is known about the effectiveness of primary stenting for very elderly patients, especially, nonagenarian patients. We therefore report two nonagenarian patients with AMI treated by primary stenting. One patient discharged from our hospital after 24 days from admission. This patient is currently being carefully followed up by the referring physician. However, the other patient developed cardiogenic shock on admission, and she unfortunately died 2 days after admission. Primary stenting might not be contraindicated even for nonagenarian patients with AMI considering the limitation of conventional therapy.

Limitations of spontaneous reperfusion and conventional medical therapy to afford myocardial protection through antecedent angina pectoris in acute myocardial infarction

Despite the cardioprotective effect of rapid coronary reperfusion, the effects of spontaneous recanalization on myocardial viability and metabolism are unknown. We studied whether preinfarction angina affords cardioprotection when spontaneous coronary reperfusion occurred in acute infarct patients. Myocardial tomographies with thallium and I-123-labeled-β-methyl-p-iodophenyl penta-decanoic acid (BMIPP) were performed in 27 acute myocardial infarct patients treated medically: 15 patients had preexisting angina before infarction (group A) and 12 did not (group B). Thallium and BMIPP abnormalities and regional function were quantified by a polar map and contrast ventriculography, respectively. There was no significant difference between thallium and BMIPP in the severity index in groups A and B (89 ± 97 vs. 85 ± 68, 97 ± 28 vs. 95 ± 27, respectively), and no significant difference between the groups in the thallium or BMIPP severity index. The ratio of the thallium severity index to that of BMIPP and the regional wall-motion abnormality index were identical in groups A and B. Both patient groups were divided into 2 subgroups based on the presence or absence of spontaneous coronary reperfusion: subgroups A1 and A2, and subgroups B1 and B2, respectively. There were no significant differences among the 4 subgroups in severity indexes for both tracers, the thallium/BMIPP ratio, or the asynergy score. The BMIPP severity index correlated significantly with that of thallium in all subgroups, but no significant difference between the regression lines was found. It is therefore unlikely that spontaneous coronary recanalization affords beneficial effects through preservation of myocardial viability in an ischemia-related zone, suggesting that the cardioprotective effect of preinfarction angina is a limited phenomenon in patients undergoing rapid coronary reperfusion.