Potential Effects of Ischemic Postconditioning and Changes in Heat Shock Protein 72 in Patients with Acute Myocardial Infarction without Prodromal Angina.

The effectiveness of ischemic postconditioning (iPoC) in patients with ST-elevation myocardial infarction (STEMI) without ischemic preconditioning has not been determined. Therefore, we investigated the impact of iPoC and its potential mechanism related to heat shock protein 72 (HSP72) induction on myocardial salvage in patients with STEMI without prodromal angina (PA).We retrospectively analyzed data from 102 patients with STEMI with successful reperfusion among 323 consecutive patients with acute coronary syndrome. Among these, 55 patients with iPoC (iPoC (+) ) underwent 4 cycles of 60-second inflation and 30-second deflation of the angioplasty balloon. Both the iPoC (+) and iPoC (-) groups were divided into 2 further subgroups: patients with PA (PA (+) ) and those without (PA (-) ). We analyzed HSP72 levels in neutrophils, which were measured until 48 hours after reperfusion. I-123 ß-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) scintigraphy was performed within a week of reperfusion therapy. In 64% of patients, thallium-201 (TL) scintigraphy was performed 6-8 months after STEMI onset.Using BMIPP and TL, in the PA (-) subgroups, the iPoC (+) group had a significantly greater myocardial salvage ratio than the iPoC (-) group. iPoC was identified as an independent predictor of the myocardial salvage ratio. The HSP72 increase ratio was significantly elevated in the iPoC (+) PA (-) group. Importantly, the myocardial salvage effect in patients without PA was significantly correlated with the HSP72 increase ratio, which was greater in patients with iPoC.These results suggest the potential impact of iPoC via HSP72 induction on myocardial salvage; however, the effects may be limited to patients with STEMI without PA.

Sustaining self-restraint until the middle of the COVID-19 pandemic in Tokyo.

We analyzed time-series changes in people's purpose-specific mobility characteristics owing to the COVID-19 pandemic in the Tokyo area of Japan, where only legally non-binding requests for self-restraint were enforced. A multiple regression analysis was conducted with the objective variable being the mobile population in the Tokyo area per 500 m square grid estimated from mobile spatial statistical data for 2 years from 10/01/2019 to 9/30/2021. This study period ranges from pre- to mid-pandemic. The explanatory variable was the number of buildings by type per 500 m square grid obtained from building statistical data to determine behavioral changes by mobility purpose. The analysis revealed that self-restraint was sustained until the middle of the COVID-19 pandemic in the Tokyo area regardless of the purpose of mobility and whether a state of emergency was declared.

Questionnaire in patients with aborted sudden cardiac death due to coronary spasm in Japan.

OBJECTIVES: We investigated the medical or mechanical therapy, and the present knowledge of Japanese cardiologists about aborted sudden cardiac death (ASCD) due to coronary spasm. METHODS: A questionnaire was developed regarding the number of cases of ASCD, implantable cardioverter-defibrillator (ICD), and medical therapy in ASCD patients due to coronary spasm. The questionnaire was sent to the Japanese general institutions at random in 204 cardiology hospitals. RESULTS: The completed surveys were returned from 34 hospitals, giving a response rate of 16.7%. All SCD during the 5 years was observed in 5726 patients. SCD possibly due to coronary spasm was found in 808 patients (14.0%) and ASCD due to coronary spasm was observed in 169 patients (20.9%). In 169 patients with ASCD due to coronary spasm, one or two coronary vasodilators was administered in two-thirds of patients [113 patients (66.9%)], while more than 3 coronary vasodilators were found in 56 patients (33.1%). ICD was implanted in 117 patients with ASCD due to coronary spasm among these periods including 35 cases with subcutaneous ICD. Majority of cause of ASCD was ventricular fibrillation, whereas pulseless electrical activity was observed in 18 patients and complete atrioventricular block was recognized in 7 patients. Mean coronary vasodilator number in ASCD patients with ICD was significantly lower than that in those without ICD (2.1 ± 0.9 vs. 2.6 ± 1.0, p < 0.001). Although 16 institutions thought that the spasm provocation tests under the medications had some clinical usefulness of suppressing the next fatal arrhythmias, spasm provocation tests under the medication were performed in just 4 institutions. CONCLUSIONS: In the real world, there was no fundamental strategy for patients with ASCD due to coronary spasm. Each institution has each strategy for these patients. Cardiologists should have the same strategy and the same knowledge about ASCD patients due to coronary spasm in the future.

Initial reduction of oxidative stress by angiotensin receptor blocker contributes long term outcomes after percutaneous coronary intervention.

BACKGROUND: It remains unclear whether administration of ARB with reactive oxygen species (ROS) scavenging effects improves the prognosis of patients undergoing PCI. OBJECTIVES: This study investigated whether the pre-intervention antioxidant effect of angiotensin receptor blocker (ARB) affects long-term outcomes in patients after successful percutaneous coronary intervention (PCI) without early adverse events. METHODS: Fifty-two patients who underwent elective PCI were randomly assigned for treatment with or without ARB, which was administered within 48 hours before PCI. ROS levels in mononuclear cells (MNCs) and serum superoxide dismutase (SOD) activity were measured pre-PCI and 6 months post-PCI. After exclusion of unexpected early adverse events during angiographic follow-up period, the long-term outcome (major adverse cerebro-cardiovascular event; MACCE) was assessed in eligible patients. RESULTS: Forty-three patients (non-ARB n = 22, ARB n = 21) were followed up in this study. During angiographic follow-up period, ROS formation in MNCs was significantly increased in the non-ARB group (from 29.4 [21.6-35.2] to 37.2 [30.7-45.1] arbitrary units; p = 0.031) compared to that in the ARB group. Meanwhile, SOD activity was significantly impaired in the non-ARB group alone (from 24.0 ± 17.0 to 16.3 ± 13.8%, p = 0.004). During the follow-up period (median, 63.3 months), MACCEs were observed in 6 patients. The cumulative event ratio of MACCE was significantly higher in the non-ARB group than in the ARB group (p = 0.018). CONCLUSIONS: Concomitant administration of ARB effectively reduced ROS production of PCI patients during angiographic follow-up period. Initial ROS inhibition following ARB administration may contribute to improvement of worse outcomes in patients who have undergone successful PCI.

Ischemic preconditioning effect of prodromal angina is attenuated in acute myocardial infarction patients with hypertensive left ventricular hypertrophy.

BACKGROUND: Several animal experiments on acute myocardial infarction (AMI) have shown that the cardioprotective effects of ischemic preconditioning are more significant in hypertensive subjects. However, because there are no clinical data on the impact of hypertension on ischemic preconditioning in patients with AMI, whether clinical ischemic preconditioning of prodromal angina was beneficial in AMI patients with hypertension was investigated in the present study. METHODS AND RESULTS: 125 patients with a first anterior AMI who had undergone successful reperfusion therapy were divided into 2 groups, with or without hypertension, and into 2 further subgroups based on the presence or absence of prodromal angina. Dual-isotope (thallium-201(TL)/Tc-99m pyrophosphate) single-photon emission computed tomography (SPECT) was performed within 1 week of reperfusion therapy. Left ventricular (LV) function and LV mass index (LVMI) were measured by left ventriculography and echocardiography, respectively. In patients without hypertension, prodromal angina resulted in significantly less myocardial damage on TL-SPECT, better LV ejection fraction and a greater myocardial blush grade compared to patients without prodromal angina. However, these cardioprotective effects of prodromal angina were significantly diminished in hypertensive patients. Importantly, the myocardial salvage effects of prodromal angina showed a significant negative correlation with LVMI, which was significantly greater in hypertensive patients. CONCLUSIONS: The cardioprotective effects of prodromal angina were attenuated in patients with hypertension. Hypertensive LV hypertrophy may crucially limit the effects of ischemic preconditioning in AMI.

Tachycardia-induced myocardial ischemia and diastolic dysfunction potentiate secretion of ANP, not BNP, in hypertrophic cardiomyopathy.

The aim of this study was to investigate what factor determines tachycardia-induced secretion of atrial and brain natriuretic peptides (ANP and BNP, respectively) in patients with hypertrophic cardiomyopathy (HCM). HCM patients with normal left ventricular (LV) systolic function and intact coronary artery (n = 22) underwent rapid atrial pacing test. The cardiac secretion of ANP and BNP and the lactate extraction ratio (LER) were evaluated by using blood samples from the coronary sinus and aorta. LV end-diastolic pressure (LVEDP) and the time constant of LV relaxation of tau were measured by a catheter-tip transducer. These parameters were compared with normal controls (n = 8). HCM patients were divided into obstructive (HOCM) and nonobstructive (HNCM) groups. The cardiac secretion of ANP was significantly increased by rapid pacing in HOCM from 384 +/- 101 to 1,268 +/- 334 pg/ml (P < 0.05); however, it was not significant in control and HNCM groups. In contrast, the cardiac secretion of BNP was fairly constant and rather significantly decreased in HCM (P < 0.01). The cardiac ANP secretion was significantly correlated with changes in LER (r = -0.57, P < 0.01) and tau (r = 0.73, P < 0.001) in HCM patients. Tachycardia potentiates the cardiac secretion of ANP, not BNP, in patients with HCM, particularly when it induces myocardial ischemia and LV diastolic dysfunction.

Relationship between the parameters of retinal circulation measured by laser Doppler velocimetry and a marker of early systemic atherosclerosis.

PURPOSE: To examine the relation between intima-media thickness (IMT) in the common carotid artery, which is generally recognized as a marker of early atherosclerosis, and retinal circulatory parameters. METHODS: The vessel diameter and blood velocity of retinal arterioles were measured with laser Doppler velocimetry (LDV) in 33 patients with coronary artery disease (CAD), because they were thought to have general atherosclerosis. The retinal blood flow (RBF) and wall shear rate (WSR), an index of wall shear stress in retinal vessels, were calculated from the two parameters. The carotid IMT was evaluated with B-mode ultrasonography. RESULTS: The patients were divided into two groups: those with an IMT >0.70 mm and those with an IMT < or =0.70 mm. The blood velocity, WSR, and upstroke time in the retinal arterioles were significantly higher in the group with an IMT >0.70 mm compared with the group with an IMT < or =0.70 mm. There were no significant differences in vessel diameter and RBF between the groups. Positive correlations were found between the carotid IMT and blood velocity (r = 0.51, P = 0.002) and WSR (r = 0.60, P = 0.0001). Multiple regression analysis showed that the retinal WSR and blood velocity correlated independently with the IMT in patients with CAD. CONCLUSIONS: The present findings from this pilot study suggest that the retinal circulatory parameters measured by LDV may be associated with systemic atherosclerosis. These results support recent studies showing an association between retinal microvascular changes and cardiovascular disease.

Recovery of BMIPP uptake and regional wall motion in insulin resistant patients following angioplasty for acute myocardial infarction.

The effect of insulin resistance (IR) on the fatty acid metabolism of myocardium, and therefore on the recovery of left ventricular (LV) wall motion, has not been established in patients with acute myocardial infarction (AMI). A total of consecutive 58 non-diabetic AMI patients who had successfully undergone emergency coronary angioplasty were analyzed retrospectively. They were categorized into 2 groups, normal glucose tolerance (NGT) and impaired glucose tolerance (IGT), based on a 75-g oral glucose tolerance test (OGTT). The parameters of OGTT, myocardial scintigraphy (n=58) (thallium-201 (Tl) and iodine-123-beta-methyl-iodophenylpentadecanoic acid (BMIPP)) and left ventriculography (n=24) were compared in the 2 groups after reperfusion (acute phase) and 3-4 weeks after the AMI (chronic phase). The insulin resistance (IR), estimated by the serum concentration of insulin at 120 min (IRI 120') of the OGTT and by the HOMA (the homeostasis model assessment) index, was higher in the IGT group than in NGT group. An inverse correlation was found between the recovery of regional LV wall motion in the ischemic lesion and the IRI 120' and HOMA index. Although the recovery of BMIPP uptake from the acute to the chronic phase was higher in the IGT group, it was only correlated with the degree of IRI 120', not with the HOMA. IR accompanied by IGT can negatively influence the recovery of regional LV wall motion.