Takahisa Yamada

Prediction of Transition to Chronic Atrial Fibrillation in Patients With Paroxysmal Atrial Fibrillation by Signal- Averaged Electrocardiography A Prospective Study

BACKGROUNDnIt is well known that paroxysmal atrial fibrillation (PAF) often precedes the establishment of chronic atrial fibrillation (CAF). However, there have been no definite methods to predict the transition from PAF to CAF. The purpose of this report was to determine prospectively whether P-wave-triggered signal-averaged ECG (P-SAE) is useful for the prediction of the transition to CAF in patients with PAF.nnnMETHODS AND RESULTSnOne hundred twenty-two consecutive patients with PAF were prospectively followed after P-SAE, echocardiography, and 24-hour Holter monitoring at study entry. The duration (Ad) and root-mean-square voltage for the last 30 ms (LP30) of the filtered P wave were measured in P-SAE. The abnormality of P-SAE for the prediction of transition to CAF was defined as Ad > or = 145 ms and LP30 < 3.0 microV. Twenty-three (19%; group 1) of the patients had the abnormality of P-SAE, whereas the others (group 2) did not. During the follow-up period (mean, 26+/-12 months), 10 patients (43%) in group 1 acquired CAF, whereas the transition to CAF was observed in only 4 patients (4%) in group 2. Kaplan-Meier analysis revealed that the transition to CAF was significantly observed more often in group 1 than in group 2 (log-rank test, P<.0001). The Cox proportional hazards regression model identified that the variables most significantly associated with the transition to CAF were Ad (chi2=8.6, P=.003) and LP30 (chi2=5.1, P=.02), although significant differences in the left atrial dimension (40.8+/-5.3 versus 37.3+/-5.5 mm, P<.01) and the number of atrial premature contractions (3641+/-4524 versus 1489+/-2895 beats/d, P<.05) were observed between groups 1 and 2.nnnCONCLUSIONSnThese results indicate that P-SAE could be useful to identify patients at risk for the transition from PAF to CAF.

Outcomes of the largest multi-center trial stratified by the presence of diabetes mellitus comparing sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in patients with coronary artery disease. The Japan drug-eluting stents evaluation: a randomized trial (J-DESsERT)

The Japan drug-eluting stents evaluation: a randomized trial (J-DESsERT) was conducted to compare the effectiveness of 2 different drug-eluting stents (DES). It remains uncertain which is more efficacious in diabetic patients, sirolimus-eluting stents (SES) or paclitaxel-eluting stents (PES). In this trial, the largest of its kind, 3,533 patients including 1,724 diabetes mellitus (DM) patients were randomized to either SES or PES. Stratification was based on the presence or absence of DM. PES target vessel failure (TVF) non-inferiority at 8xa0months (primary endpoint) was not demonstrated when compared to SES (SES 4.5xa0% vs. PES 6.4xa0%, pxa0=xa00.23). In addition, PES TVF superiority at 8xa0months in the DM subset (secondary endpoint) was not shown (SES 5.6xa0% vs. PES 7.6xa0%, pxa0=xa00.10). Insulin treatment was associated with increased TVF rates, however, this was less pronounced in the PES group. At 8xa0months, the similar TVF rates for SES and PES up to that point diverged significantly, favoring SES out to 12xa0months. Patients undergoing routine angiographic follow-up demonstrated lower TVF prior to the 8-month point, and higher TVF after 8xa0months, as compared to those followed clinically. In conclusion, the current study failed to demonstrate the proposed superiority of PES for DM patients. In addition, the diversion of TVF at 8xa0months may reflect an “oculo-stenotic reflex” bias (the tendency to treat lesions found during routine, rather than clinically driven, angiographic follow-up), which could constitute an obstacle for evaluating the true clinical effect of new devices.

Increased intraatrial conduction abnormality assessed by P-wave signal-averaged electrocardiogram in patients with Brugada syndrome.

Background: u2002Atrial fibrillation (AF) is observed in patients with Brugada syndrome (BS), especially those showing coved‐type electrocardiogram (ECG) pattern. Using P‐wave signal‐averaged ECG (P‐SAE), we investigated whether increased intraatrial conduction abnormality contributed to AF generation in BS patients.

Impact of atrial fibrillation ablation on cardiac sympathetic nervous system in patients with and without heart failure

BACKGROUND/OBJECTIVESnCatheter ablation of atrial fibrillation (AF) might influence the cardiac autonomic nervous system. To investigate the impact of catheter ablation on the sympathetic nervous function in AF patients with and without heart failure (HF) using cardiac iodine-123-metaiodobenzylguanidine ((123)I-mIBG) scintigraphy, and the association of this effect with AF recurrence.nnnMETHODSnForty consecutive patients (median age, 65 (54-69) years; male, 29) with paroxysmal (n=22) and persistent (n=18) AF who were scheduled for ablation were enrolled. Twelve (30%) of these patients also exhibited either stable HF, defined as an ejection fraction <40%, or a history of symptomatic HF. (123)I-mIBG scintigraphy was performed at baseline and 3months post-ablation. The heart-to-mediastinum ratio of (123)I-mIBG uptake at 15min (H/M15min) and 240min (H/M240min), as well as the washout rate (WR) were measured.nnnRESULTSnDuring an 11±4-month follow-up, AF recurrence was observed in 8 (20%) patients receiving no antiarrhythmic drugs. Patients with HF had a tendency toward a lower baseline H/M15min (1.91±0.06 vs. 2.05±0.04, p=0.07), significantly lower H/M240min (1.88±0.22 vs. 2.14±0.28, p=0.008), and higher WR (40.3±9.0 vs. 32.3±7.4, p=0.007). Post-ablation, WR decreased in patients with HF (40.2±8.5 to 29.0±8.9, p=0.02) but slightly increased in those without (32.0±7.4 to 34.6±10.3, p=0.04). WR post-ablation independently predicted AF recurrence (adjusted hazard ratio=1.14 for 1 percentage point increase in the WR, 95% coincidence interval=1.02-1.34, p=0.02).nnnCONCLUSIONSnAF ablation restores sympathetic nervous system status via attenuation of excessive adrenergic tone in HF patients. Elevated sympathetic nervous tone 3months post-ablation was a reliable predictor of AF recurrence.

Three-year follow-up outcomes of SES and PES in a randomized controlled study stratified by the presence of diabetes mellitus: J-DEsSERT trial

BACKGROUNDnThree-year clinical follow-up of patients with diabetes mellitus (DM) in the Japan-Drug Eluting Stents Evaluation; a Randomized Trial (J-DESsERT) using 2 different drug eluting stents (DES). A recent study demonstrated that efficacy of sirolimus eluting stents (SES) attenuated over time in diabetic patients.nnnMETHODSnIn the largest trial of its kind, 1724 DM patients out of 3533 enrolled patients were randomized to either SES or paclitaxel eluting stents (PES).nnnRESULTSnThere were no significant differences in baseline clinical characteristics aside from hypertension. Incidence of major adverse cardiac cerebrovascular events (MACCE) mainly due to higher target vessel failure (TVF) initially indicated a benefit in SES (MACCE rate at 1 year: SES 9.4%, PES 12.2%, p=0.08); however this had attenuated by the time of the 3-year follow-up (MACCE rate from 1 to 3 years: SES 8.4%, PES 6.1%, p=0.10). A similar pattern was observed in insulin-treated patients: MACCE rate from 1 to 3 years was 10.5% in SES and 6.4% in PES (p=0.25). Angiographic follow-up also resulted in higher major adverse cardiac event (MACE) rates at 1 year (presence 11.5%, absence 8.3%, p=0.04); however by 3 years rates were similar regardless of the presence of angiographic follow-up (MACE rate at 3 years: presence 16.0%, absence 14.5%, p=0.35).nnnCONCLUSIONSnThe superiority of SES over PES in MACCE at 1 year had attenuated by 3-year follow-up. Eventually, the 3-year safety and efficacy profiles were similar regardless of insulin treatment.

Low-Dose Erythropoietin in Patients With ST-Segment Elevation Myocardial Infarction (EPO-AMI-II) ― A Randomized Controlled Clinical Trial ―

BACKGROUNDnErythropoietin (EPO) has antiapoptotic and tissue-protective effects, but previous clinical studies using high-dose EPO have not shown cardioprotective effects, probably because of platelet activation and a lack of knowledge regarding the optimal dose. In contrast, a small pilot study using low-dose EPO has shown improvement in left ventricular function without adverse cardiovascular events.Methodsu2004andu2004Results:We performed a multicenter (25 hospitals), prospective, randomized, double-blind, placebo-controlled, dose-finding study to clarify the efficacy and safety of low-dose EPO in patients with ST-segment elevation myocardial infarction (STEMI) under the Evaluation System of Investigational Medical Care of the Ministry of Health, Labor and Welfare of Japan. In total, 198 STEMI patients with low left ventricular ejection fraction (LVEF <50%) were randomly assigned to receive intravenous administration of EPO (6,000 or 12,000 IU) or placebo within 6 h of successful percutaneous coronary intervention. At 6 months, there was no significant dose-response relationship in LVEF improvement among the 3 groups tested (EPO 12,000 IU: 5.4±9.3%, EPO 6,000 IU: 7.3±7.7%, Placebo: 8.1±8.3%, P=0.862). Low-dose EPO also did not improve cardiac function, as evaluated by 99 mTc-MIBI SPECT or NT-proBNP at 6 months and did not increase adverse events.nnnCONCLUSIONSnAdministration of low-dose EPO did not improve LVEF at 6 months in STEMI patients (UMIN000005721).

The signal averaged ECG in the detection of sinus atrial abnormalities

With the recent interest in developing methods to record intracardiac microvolt potentials from the body surface, signal averaging techniques for accurate assessment have been actively sought1–5 in connection with ventricular tachycardia or sudden death. However, there have been few such studies for atrial arrhythmias.

Can Aminophylline Improve Exercise Capacity in Patients with Coronary Artery Disease

Aminophylline (Am) a potent adenosine receptor blocker, may increase transmural blood flow in the ischemic myocardium by preventing the maldistribution of coronary flow, although this agent is known to elevate myocardial oxygen consumption. To determine whether aminophylline does have this action, symptom-limited ramp-fashioned treadmill stress testing, combined with gas exchange analysis, was performed in 20 patients with coronary heart disease. In the first stress testing, Am (7 mg/kg) was administered over a 20-min period just before exercise. The second stress testing, the control study, was carried out without Am. There were no significant differences in basal heart rate, systolic blood pressure, rate-pressure product or oxygen consumption (VO2) before exercise, in the two studies with without Am. After the administration of Am, heart rate increased (72 ± 13 to 80 ± 16 bpm; mean ± SD, P < 0.05), as did rate-pressure product (96 ± 28 to 108 ± 33 mmHg × bpm × 100, P < 0.05), although the systolic blood pressure and VO2 did not show significant changes. During exercise, Am effected a significant increase in exercise duration (8.9 ± 2.6 versus 10.4 ± 2.8 min, P < 0.01). The rate-pressure product recorded at peak exercise was also significantly higher after Am (212 ± 56 versus 251 ± 74 mmHg × bpm × 100, P < 0.05). However, there was no significant difference in ST segment change in ECG at the end-point of exercise between the two study groups, with and without Am. Moreover, exercise maximal VO2 (20.5 ±5.1 versus 21.6 ± 6.5 ml/min) and anaerobic threshold (14.8 ± 2.7 versus 14.8 ± 2.8 ml/min) were not significantly different in the two study groups. These findings indicate that administration of Am to patients with coronary artery disease does not induce deterioration, but rather improves exercise capacity.