Takashi Akima

Endothelium-dependent flow-mediated vasodilation in coronary and brachial arteries in suspected coronary artery disease.

Previous studies showed a weak correlation between endothelial function of the coronary arteries as assessed by acetylcholine and brachial artery vasomotion during reactive hyperemia. When the same stimulus was used, we obtained a strong correlation between flow-mediated dilation in the coronary and brachial arteries (r=0.78, p <0.001), so that noninvasive assessment of flow-mediated dilation in the brachial artery could be used as a surrogate measure for coronary artery endothelial function.

Arterial remodeling influences the development of intimal hyperplasia after stent implantation

OBJECTIVES We examined whether preinterventional arterial remodeling influenced the interventional results after stenting. BACKGROUND Arterial remodeling is seen in atherosclerotic lesions, and it may play an important role in the early stage of atherosclerosis. METHODS We examined 113 lesions that underwent elective stenting using tubular slotted stents under intravascular ultrasound guidance. The lesions were divided into three groups--adequate, intermediate and inadequate remodeling group--according to preinterventional arterial remodeling. The patients were subjected to coronary angiography and intravascular ultrasound evaluation on average 6.4 months after stenting. RESULTS At baseline and immediately after stenting, there were no differences in quantitative angiographic analysis among remodeling groups. However, the plaque cross-sectional area (CSA) in the minimal lumen CSA at preintervention and intimal hyperplasia CSA at follow-up were significantly larger in the adequate remodeling group than in the inadequate remodeling group. The restenosis rate of stenting for the lesions with inadequate arterial remodeling was very low (9.4%). A significant positive correlation was found between preinterventional plaque CSA and intimal hyperplasia CSA at follow-up (r = 0.47, p < 0.0001). Moreover, remodeling index significantly correlated with relative intimal hyperplasia CSA (r = 0.28, p < 0.01). CONCLUSIONS Preinterventional arterial remodeling influenced the development of intimal hyperplasia after stenting.

Effect of Quinapril versus Nitrendipine on endothelial dysfunction in patients with systemic hypertension

linearly related to CAD severity in women, which likely explains the stronger association with clinical events and mortality. No such relation was observed for men. In women, CAD was predicted by metabolic syndrome risk factors, and the association with uric acid reflects this risk factor pattern. Regardless of whether hyperuricemia is an independent risk factor, it identifies a high-risk subset of women. For men, the best predictors of CAD were advanced age and microalbuminuria.

Impact of postconditioning with lactate-enriched blood on in-hospital outcomes of patients with ST-segment elevation myocardial infarction

BACKGROUND Reperfusion injury offsets the beneficial effects of reperfusion therapy for ST-segment elevation myocardial infarction (STEMI). In our previous reports, postconditioning with lactate-enriched blood (PCLeB) induced excellent microcirculation recovery and less inflammation in STEMI patients. This study aimed to determine the in-hospital outcomes of STEMI patients treated using PCLeB. METHODS Fifty-five consecutive STEMI patients were treated using PCLeB (Age 66.6±13.8years, 76.4% men) within 12h of symptom onset. In our modified postconditioning protocol, the duration of each brief reperfusion was prolonged from 10s to 60s in a stepwise manner. Lactated Ringers solution (20-30mL) was injected directly into the culprit coronary artery at the end of each brief reperfusion and the balloon was quickly inflated at the lesion site, whereby lactate could be trapped inside the ischemic myocardium. Each brief ischemic period lasted 60s. After 7cycles of balloon inflation and deflation, full reperfusion was performed. Thereafter, stenting was performed and percutaneous coronary intervention (PCI) was completed. RESULTS The mean corrected thrombolysis in myocardial infarction frame count was 20.1±10.1 after PCI completion. The mean peak serum creatine kinase and creatine kinase-MB levels were 2751±2227IU/L and 276±181IU/L respectively. None of the study patients died during their hospital stay or required continuation of oral diuretic or inotropic therapy for heart failure on discharge. CONCLUSIONS PCLeB led to zero in-hospital mortality and no overt heart failure on discharge in 55 consecutive STEMI patients undergoing reperfusion therapy.

Muscle squeezing immediately after coronary reperfusion therapy using postconditioning with lactate-enriched blood

BACKGROUND We recently reported a new approach for cardioprotection, postconditioning with lactate-enriched blood (PCLeB), and a patient with ST-segment elevation myocardial infarction (STEMI), in whom muscle squeezing of the culprit coronary artery was observed immediately after reperfusion with PCLeB. In this study, we examined the prevalence of muscle squeezing immediately after reperfusion in patients with anterior STEMI treated using PCLeB. METHODS AND RESULTS PCLeB is a modified postconditioning protocol that comprises intermittent reperfusion and timely coronary injections of lactated Ringers solution. We treated 30 consecutive patients with anterior STEMI using PCLeB. Among the 30 patients, 4 patients exhibited muscle squeezing of the left anterior descending artery (LAD) immediately after reperfusion. We performed follow-up coronary angiography in 23 patients and found another patient who exhibited muscle squeezing of the LAD. Thus, of 30 patients, 5 were confirmed to have myocardial bridging and 4 exhibited muscle squeezing immediately after reperfusion with PCLeB. No patient died or experienced re-hospitalization for heart failure or recurrent ischemic events at 6 months except for one patient with malignancy. CONCLUSION Muscle squeezing immediately after reperfusion therapy is not a rare phenomenon in patients with anterior STEMI treated using PCLeB.

Altered fractal behavior and heart rate variability in daily life in neurally mediated syncope

Autonomic imbalance is thought to play an important role in the pathogenesis of neurally mediated syncope (NMS). Heart rate variability (HRV) indices and fractal dimension derived from 24 h ambulatory electrocardiogram (AECG) reflects the cardiac autonomic activity and provides useful information for understanding the pathogenesis of NMS. In this study, we sought the cardiac autonomic activity and the status of fractal dimension in daily life in patients with NMS. The 24 h ambulatory ECG recordings were performed in 36 NMS patients (NMS group) and in 11 healthy volunteers (CTRL group). Six time domain and frequency domain HRV indices were calculated. The regression of log (power) on log (frequency) was also calculated and the slope of the regression line (beta) was analyzed in three different periods such as total 24 h, awake and sleep phases. The values of mean RR, SDNN and SDANN were not significantly different, but the values of S.D. index, rMSSD, pNN50 and all the frequency domain HRV indices were significantly higher in NMS group than in CTRL group. For 24-h period, there was no significant difference in the values of beta. For awake phase, the value of beta was significantly higher in NMS group than in CTRL group. For sleep phase, the value of beta was significantly lower in NMS group than in CTRL group. Augmented autonomic activity and the deterioration of fractal dimension in daily life might contribute to the pathogenesis of NMS.