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Little evidence is available regarding the long-term outcome in elderly patients after deferral of revascularization based on fractional flow reserve (FFR).Methods and Results: From the J-CONFIRM registry (long-term outcomes of Japanese patients with deferral of coronary intervention based on fractional flow reserve in multicenter registry), 1,262 patients were divided into 2 groups according to age: elderly and younger patients (aged ≥75 or75 years, respectively). The primary endpoint was the cumulative 5-year incidence of target vessel failure (TVF), defined as a composite of cardiac death, target vessel-related myocardial infarction (TVMI), and clinically driven target vessel revascularization (CDTVR). Cumulative 5-year incidence of TVF was not significantly different between elderly and younger patients (14.3% vs. 10.8%, P=0.12). Cardiac death occurred more frequently in elderly patients than younger patients (4.4% vs. 0.8%, P0.001), whereas TVMI and CDTVR did not differ between groups (1.3% vs. 0.9%, P=0.80; 10.7% vs. 10.1%, P=0.80, respectively). FFR values in lesions with diameter stenosis50% were significantly higher in elderly patients than in younger patients (0.88±0.07 vs. 0.85±0.07, P=0.01), whereas this relationship was not observed in those with diameter stenosis ≥50%.Elderly patients had no excess risk of ischemic events related to the deferred coronary lesions by FFR, although FFR values in mild coronary artery stenosis were modestly different between elderly and younger patients.

The aim of this study was to evaluate the impact of thrombotic risk on the occurrence of cardiovascular events in patients with coronary artery disease with deferred revascularization after fractional flow reserve (FFR) measurements.Deferral of revascularization on the basis of FFR is generally considered to be safe, but after deferral, some patients have cardiovascular events over time.From J-CONFIRM registry (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry), 1,263 patients with deferral of revascularization on the basis of FFR were evaluated. The association between thrombotic risk as assessed by CREDO-Kyoto (Coronary Revascularization Demonstrating Outcome Study in Kyoto) thrombotic score and 5-year target vessel failure (TVF) and major adverse cardiac and cerebrovascular events (MACCE) was investigated.FFR and high thrombotic risk (HTR) were associated with increased risk for 5-year TVF (FFR per 0.01-unit decrease: HR: 1.08; 95% CI: 1.05-1.11; P 0.001; HTR: HR: 2.16; 95% CI: 1.37-3.39; P 0.001) and MACCE (FFR per 0.01-unit decrease: HR: 1.05; 95% CI: 1.02-1.06; P 0.001; HTR: HR: 2.11; 95% CI: 1.56-2.84; P = 0.001). Patients with HTR had higher risk for 5-year TVF (HR: 2.30; 95% CI: 1.45-3.66; P 0.001) and MACCE (HR: 2.34; 95% CI: 1.75-3.13; P 0.001) than those without HTR, even when they had negative FFR.Assessment of thrombotic risk provides additional prognostic value to FFR in predicting 5-year TVF and MACCE in patients with deferral of revascularization after FFR measurements. (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry; UMIN000014473).

The purpose of this study was to evaluate the initial and long-term outcomes of Percutaneous Transluminal Angioplasty (PTA) for central venous stenosis or occlusion in chronic hemodialysis patients. A total of 363 central venous lesions (277 stenosis and 86 occluded lesions) of 146 patients were enrolled and analyzed retrospectively; these included 130 de novo lesions and 233 restenosis lesions. The procedural success rate in our cohort was 97.0% (352/363 lesions); success rate for stenosis was significantly higher than that for occluded lesions (99.3% vs. 89.5%, P < 0.001). Complications during PTA procedures occurred in nine lesions (2.5%); however, there were no serious complications. A total of 120 stents were implanted for 111 lesions; the rate of stent placement for occluded lesions was significantly higher than that for stenosis lesions (68.8% vs. 18.4%, P < 0.001). The primary patency of de novo lesions was significantly higher than that of restenosis lesions (P = 0.0004); the assisted patency of de novo lesions at 12 and 36 months were 94.4% and 89.0%, respectively. There was no significant difference of primary patency between balloon angioplasty and stent placement for de novo lesions, however, primary patency after stent placement for restenosis lesions was significantly higher than that after balloon angioplasty (P = 0.001). In conclusion, PTA for central venous stenosis or occlusion was safe procedure with low rate of technical failure. The patency of vascular access in long-term was maintained by the repeated intervention. Stent placement could help prolong the patency period for restenosis lesions.

This study aims to explore the associations between uric acid (UA) and long-term outcomes among patients with acute coronary syndrome (ACS). A total of 1068 consecutive patients with ACS who underwent percutaneous coronary intervention (PCI) were analyzed retrospectively. The patients were divided into 3 groups based on the levels of serum UA upon admission (bottom quintile, middle 3 quintiles, and top quintile). The primary endpoint was all-cause mortality. The patients in the higher UA groups were associated with younger age (71 ± 11 versus 68 ± 12 versus 67 ± 14 years; P0.05) and were more likely to be male (57.6 versus 76.9 versus 84.7%; P0.001). Furthermore, these patients had lower estimated glomerular filtration rates (83 ± 27 versus 74 ± 23 versus 59 ± 24 mL/minute/1.73 m

Background: Little large-scale data is available about the long-term (beyond 3 years) clinical outcomes after fractional flow reserve (FFR)–based deferral of revascularization in clinical practice. We sought to assess the 5-year outcomes after deferral of revascularization based on FFR. Methods: The J-CONFIRM registry (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry) prospectively enrolled 1263 patients with 1447 lesions in whom revascularization was deferred based on FFR from 28 Japanese centers. The primary study end point was the cumulative 5-year incidence of target vessel failure (TVF), including cardiac death, target vessel–related myocardial infarction, and clinically driven target vessel revascularization. Results: Five-year follow-up was completed in 92.2% of patients. The 5-year TVF rate was 11.6% in deferred lesions, mainly driven by clinically driven target vessel revascularization (9.8%). Cardiac death and target vessel–related myocardial infarction were 1.9% and 0.95%, respectively. Cumulative 5-year incidence of TVF was similar between the FFR 0.75 to 0.80 and 0.81 to 0.85 groups even after adjustment for baseline characteristics (12.2% versus 13.0%, inverse probability–weighted hazard ratio, 0.86 [95% CI, 0.46–1.60]; P =0.63). Compared with the almost normal FFR (0.86–1.00) group, the significant (P Conclusions: The 5-year TVF rate was 11.6% in deferred lesions, mainly driven by clinically driven target vessel revascularization. Notably, cardiac death and target vessel–related myocardial infarction rarely occurred during the follow-up. Our findings highlight the long-term safety of FFR-based deferral of revascularization in patients with chronic coronary syndrome. Registration: URL: https://www.umin.ac.jp/ctr ; Unique identifier: UMIN000014473.

Guideline-directed medical therapy (GDMT) is essential to prevent future cardiovascular events in chronic coronary syndrome (CCS) patients. However, whether achieving optimal GDMT could improve clinical outcomes in CCS patients with deferred lesions based on fraction flow reserve (FFR) remains thoroughly investigated. We sought to evaluate the association of GDMT adherence with long-term outcomes after FFR-based deferral of revascularization in a real-world registry.This is a post-hoc analysis of the J-CONFIRM registry (long-term outcomes of Japanese patients with deferral of coronary intervention based on fractional flow reserve in multicentre registry). Optimal GDMT was defined as combining four types of medications: antiplatelet drug, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker, beta-blocker, and statin. After stratifying patients by the number of individual GDMT agents at 2 years, landmark analysis was conducted to assess the relationship between GDMT adherence at 2 years and 5-year major adverse cardiac events (MACEs), defined as a composite of all-cause death, target vessel-related myocardial infarction, clinically driven target vessel revascularization. Compared with the suboptimal GDMT group (continuing ≤3 types of medications, n = 974), the optimal GDMT group (n = 139) showed a lower 5-year incidence of MACE (5.2% vs. 12.4%, P = 0.02). The optimal GDMT was associated with a lower risk of MACE (hazard ratio: 0.41; 95% confidence interval: 0.18 to 0.92; P = 0.03).Patients with optimal GDMT were associated with better outcomes, suggesting the importance of achieving optimal GDMT on long-term prognosis in CCS patients after FFR-guided deferral of revascularization.

Although concomitant peripheral artery disease in patients with acute coronary syndrome (ACS) has been considered as a high-risk subgroup with a greater incidence of bleeding after percutaneous coronary intervention (PCI), few data exist regarding the clinical utility of the ankle-brachial index (ABI) for predicting bleeding complications, which affects the subsequent outcome.Eight hundred and twenty-four consecutive patients with ACS who underwent PCI and ABI examination were analyzed retrospectively. Decreased-ABI was defined as ABI0.9. The primary outcome was bleeding complications within 30 days, which was defined according to the Bleeding Academic Research Consortium classification grade ≥3. The secondary endpoint was all-cause death during follow-up.Of the 824 patients with ACS, 137 (16.6%) exhibited decreased-ABI. The incidence of bleeding complications was significantly higher in patients with decreased-ABI, compared with the remaining patients (21.9% vs. 6.0%, p0.001). In multivariate analysis, anemia [odds ratio (OR) 2.14], estimated glomerular filtration rate60mL/min/1.73mAssessment of ABI provides useful information for predicting 30-day bleeding complications and long-term mortality in patients with ACS after PCI.

Background Adequate improvement in fractional flow reserve (FFR) is not necessarily achieved in some cases of drug-eluting stent (DES) implantation, even when imaging confirms successful placement. We hypothesized that post-stent FFR may be associated with advanced diffuse atherosclerotic condition. We explored the relationships between FFR values after DES implantation (post-stent FFR). Methods A total of 218 patients were included in this prospective, multicenter study and were divided into two groups: adequate FFR group (post-stent FFR >0.80, n=176) and inadequate FFR group (post-stent FFR ≤0.80, n=42). The primary endpoint was a major adverse cardiovascular event (MACE) including cardiac death, non-fatal myocardial infarction (MI), unplanned coronary revascularization, and hospitalization for heart failure. The secondary endpoints were event rate of all-cause death, non-fatal MI, unplanned coronary revascularization, non-fatal stroke, and hospitalization for heart failure. Results During follow-up of 31.4±8.7 months, 34 patients (16%) had cardiovascular events. Inadequate FFR group was significantly associated with higher risk of MACE (hazard ratio: 3.86; 95% confidence interval: 1.17–12.76, p=0.026; log-rank p=0.027). In particular, the incidence of unplanned coronary revascularization on non-target lesions was significantly higher in the inadequate FFR group (log-rank p=0.031). Conclusions Post-stent FFR ≤0.80 was associated with a high incidence of non-target lesion revascularization and could be a surrogate marker for advanced atherosclerotic condition in the vessels of the entire coronary artery.

Subclinical peripheral artery disease (PAD) might be associated with pathophysiology of contrast-induced acute kidney injury (CI-AKI). We hypothesized that concomitant PAD in patients with the acute coronary syndrome (ACS) would represent a high-risk subgroup with a greater incidence of CI-AKI, both of which lead to higher mortality after percutaneous coronary intervention (PCI). Six hundred and seventy-five consecutive patients with ACS who underwent PCI and examination of ankle-brachial index (ABI) were analyzed retrospectively. The presence of PAD was defined as an ABI

Background: The safety of fractional flow reserve (FFR)-based deferral of revascularization remains to be fully established in real-world practice. We sought to assess clinical outcomes after deferral of revascularization based on FFR. Methods: The J-CONFIRM registry (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry) prospectively enrolled 1263 patients with 1447 lesions in whom revascularization was deferred based on FFR at 28 Japanese centers. The primary study end point was the cumulative 2-year incidence of target vessel failure, including cardiac death, target-vessel related myocardial infarction, and clinically driven target vessel revascularization. Results: The mean FFR was 0.86±0.06. At 2 years, the target vessel failure rate was 5.5% in deferred lesions, mainly driven by a high rate of clinically driven target vessel revascularization (5.2%), and significantly increased with decreasing FFR, especially in the proximal location. Cardiac death and target-vessel related myocardial infarction rarely occurred during the 2-year follow-up (0.41% and 0.41%, respectively). Independent predictors of 2-year target vessel failure were FFR value (per 0.01 decrease; hazard ratio [HR] 1.07 [95% CI, 1.04–1.11], P P P =0.003), hemodialysis (HR, 2.90 [95% CI, 1.11–7.58]; P =0.03), and right coronary artery lesion (HR, 1.78 [95% CI, 1.02–3.11], P =0.042). Conclusions: The J-CONFIRM registry demonstrated the 2-year target vessel failure rate was 5.5% in deferred lesions, highlighting the safety of FFR-based deferral of revascularization in daily practice. Clinical Trial Registration: URL: http://www.umin.ac.jp . Unique identifier: UMIN000014473.

OBJECTIVES To investigate the impact of stent deformity induced by final kissing balloon technique (KBT) for coronary bifurcation lesions on in-stent restenosis (ISR). BACKGROUND In experimental models, the detrimental effects of KBT have been clearly demonstrated, but few data exists regarding the impact of proximal stent deformity induced by KBT on clinical outcomes. METHODS We examined 370 coronary lesions where intravascular ultrasound (IVUS)-guided second-generation drug-eluting stent (DES) implantation for coronary bifurcation lesions was performed. Based on IVUS analysis, the stent symmetry index (minimum/maximum stent diameter) and stent overstretch index (the mean of stent diameter/the mean of reference diameter) were calculated in the proximal main vessel. RESULTS The stent symmetry index was significantly lower (0.75 ± 0.07 vs 0.88 ± 0.06, P

Although statin therapy is beneficial in the setting of acute coronary syndrome (ACS), a substantial proportion of patients with ACS still do not receive the guideline-recommended lipid management in contemporary practice. We hypothesize that the low-density lipoprotein cholesterol (LDL-C) level at the time of admission might affect patient management and the subsequent outcome. Nine-hundred and forty-two consecutive patients with ACS who underwent percutaneous coronary intervention were analyzed retrospectively. The study patients were first divided into two groups based on the LDL-C level on admission: group A (n = 267), with LDL-C

Objectives The NIPPON (Nobori Dual Antiplatelet Therapy as Appropriate Duration) study was a multicenter randomized investigation of the noninferiority of short-term versus long-term dual antiplatelet therapy (DAPT) in patients with implantation of the Nobori drug-eluting stent (DES) (Terumo, Tokyo, Japan), which has a biodegradable abluminal coating. Background The optimum duration of DAPT for patients with a biodegradable polymer-coated DES is unclear. Methods The subjects were 3,773 patients with stable or acute coronary syndromes undergoing Nobori stent implantation. They were randomized 1:1 to receive DAPT for 6 or 18 months. The primary endpoint was net adverse clinical and cerebrovascular events (NACCE) (all-cause mortality, myocardial infarction, stroke, and major bleeding) from 6 to 18 months after stenting. Intention-to-treat analysis was performed in 3,307 patients who were followed for at least 6 months. Results NACCE occurred in 34 patients (2.1%) receiving short-term DAPT and 24 patients (1.5%) receiving long-term DAPT (difference 0.6%, 95% confidence interval [CI]: 1.5 to 0.3). Because the lower limit of the 95% CI was inside the specified margin of −2%, noninferiority of short-term DAPT was confirmed. Mortality was 1.0% with short-term DAPT versus 0.4% with long-term DAPT, whereas myocardial infarction was 0.2% versus 0.1%, and major bleeding was 0.7% versus 0.7%, respectively. The estimated probability of NACCE was lower in the long-term DAPT group (hazard ratio: 1.44, 95% CI: 0.86 to 2.43). Conclusions Six months of DAPT was not inferior to 18 months of DAPT following implantation of a DES with a biodegradable abluminal coating. However, this result needs to be interpreted with caution given the open-label design and wide noninferiority margin of the present study. (Nobori Dual Antiplatelet Therapy as Appropriate Duration [NIPPON]; NCT01514227)

IntroductionFamilial hypercholesterolaemia (FH) is an autosomal-dominant inherited genetic disease. It carries an extremely high cardiovascular risk associated with significantly elevated low-density lipoprotein (LDL) cholesterol. The diagnostic rate of this disease in some European nations is quite high, due to the presence of multiple prospective registries. On the other hand, few data—and in particular multicentre data—exist regarding this issue among Japanese subjects. Therefore, this study intends to assemble a multicentre registry that aims to comprehensively assess cardiovascular risk among Japanese FH patients while taking into account their genetic backgrounds.Methods and analysisThe Hokuriku-plus FH registry is a prospective, observational, multicentre cohort study, enrolling consecutive FH patients who fulfil the clinical criteria of FH in Japan from 37 participating hospitals mostly in Hokuriku region of Japan from April 2020 to March 2024. A total of 1000 patients will be enrolled into the study, and we plan to follow-up participants over 5 years. We will collect clinical parameters, including lipids, physical findings, genetic backgrounds and clinical events covering atherosclerotic and other important events, such as malignancies. The primary endpoint of this study is new atherosclerotic cardiovascular disease (ASCVD) events. The secondary endpoints are as follows: LDL cholesterol, secondary ASCVD events and the occurrence of other diseases including hypertension, diabetes and malignancies.Ethics and disseminationThis study is being conducted in compliance with the Declaration of Helsinki, the Ethical Guidelines for Medical and Health Research Involving Human Subjects, and all other applicable laws and guidelines in Japan. This study protocol has been approved by the Institutional Review Board at Kanazawa University. We will disseminate the final results at international conferences and in a peer-reviewed journal.Trial registration numberUMIN000038210.

Although cardiovascular disease (CVD) is an important cause of death in patients on hemodialysis, evidence of a beneficial effect of percutaneous intervention (PCI) on stable heart disease is scarce. We investigated the cardiovascular outcomes of hemodialysis patients under our policy of encouraging coronary artery screening tests to the extent possible. A total of 147 hemodialysis patients have been treated in our clinic so far. In 98 of them, coronary artery screening tests were performed, three in unstable and 95 in asymptomatic patients. Significant coronary artery stenosis was detected in 29 at the first tests and in 11 during subsequent tests (40/98, 40.8%), and PCI or coronary artery bypass grafting (CABG) was performed. Multiple PCIs were needed in 21 patients. In the other 49 patients, coronary artery screening tests were not undertaken based on the nephrologist's decision or patient refusal. At the end of the study, 73 (74.5%) patients with tests, and 14 (28.6%) without tests were still outpatients (P < 0.01). Of 40 patients transferred to other hospitals for medical reasons or who died before transfer, there was cerebrovascular accident in eight, malignancy in six, congestive heart failure without CVD in four, infection in three, sudden cardiac death in one, and others 18. No patient with tests died of CVD and the only patient who died of sudden cardiac death probably due to myocardial infarction was a patient who had declined the screening tests. Coronary artery screening tests, intervention and subsequent periodic tests for asymptomatic hemodialysis patients can reduce the occurrence of cardiovascular events in this population.

Background (18)F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) is assumed to be the most useful method for evaluating the viability of the myocardium. However, there are few reports regarding serial changes in (18)F-FDG-PET images of acute myocardial infarction (AMI). We evaluated serial changes in glucose-loaded (18)F-FDG-PET, (123)I-β-methyl-p-iodophenyl-penta-decanoic acid (BMIPP) single-photon emission computed tomography (SPECT) and (99m)Tc-Tetrofosmin (TF) gated SPECT images in patients with AMI. Methods and results We enrolled 7 consecutive patients with first anterior AMI who successfully underwent percutaneous coronary intervention (PCI). (18)F-FDG-PET images were obtained in the acute, subacute, chronic, mid-term and long-term phases. (123)I-BMIPP and (99m)Tc-TF SPECT images were obtained in the subacute, chronic, mid-term and long-term phases. We determined the total defect score (TDS) for each image. The TDS of the glucose-loaded (18)F-FDG-PET, (123)I-BMIPP and( 99m)Tc-TF SPECT images indicated significant serial decrease (P (123)I-BMIPP>(99m)Tc-TF in all phases. Conclusions The defect areas of glucose-loaded (18)F-FDG-PET images were significantly larger than those of (123)I-BMIPP and( 99m)Tc-TF SPECT images during 9 months follow-up of patients with successful PCI for anterior AMI. Additionally, the impairment of glucose metabolism was prolonged.

Although Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) score based on angiographic scoring system was developed in patients with previous coronary artery bypass grafting (CABG), few data exist regarding its prognostic utility in patients undergoing percutaneous coronary intervention (PCI). We examined 272 patients with previous CABG (217 men; mean age, 70.4 ± 9.7 years) undergoing PCI. Severity of the coronary anatomy was evaluated using CABG-SYNTAX score. The primary end point of this study was cardiovascular death. The baseline CABG-SYNTAX score ranged from 2 to 53.5, with an average of 26.0 ± 10.2. In the index procedures, PCI for the native coronary accounted for nearly all patients (88%). During follow-up (median 4.1 years), 40 cardiovascular deaths had occurred. In multivariate analysis, age75 years (hazard ratio [HR] 2.82, 95% CI 1.45 to 5.52), left ventricular ejection fraction40% (HR 2.99, 95% CI 1.39 to 6.07), end-stage renal disease (HR 2.90, 95% CI 1.15 to 6.75), peripheral artery disease (HR 2.20, 95% CI 1.10 to 4.64), and CABG-SYNTAX score25 (HR 2.37, 95% CI 1.19 to 5.05) were independent predictors of cardiovascular death. After creating a composite risk score in consideration of identified predictors, the freedom from cardiovascular death at 5 years was 98%, 86%, and 58% in the low (0 to 1), medium (2), and high (3 to 5) scores, respectively (p0.001). The area under the receiver-operating characteristic curve for cardiovascular death for the CABG-SYNTAX and composite risk scores were 0.66 and 0.77, respectively (p0.05). In conclusion, the combination of angiographic and clinical characteristics is useful for risk stratification in patients with previous CABG undergoing PCI.

Although antiplatelet medication is used in various situations, including for the prevention of ischemic and thrombotic complications, long-term antiplatelet therapy in hemodialysis patients who are at high risk of bleeding may result in a harmful bleeding tendency. We investigated bleeding events that required the cessation of the use of heparin for hemodialysis in all the hemodialysis patients treated in our clinic. This analysis revealed 111 patients, of whom 52 had been treated with antiplatelet agents (female/male, 15/37; age, 70.4 ± 11.3 years; number of days of hemodialysis treatment in our clinic, 1073 ± 696 [31–2144] days; diabetes mellitus [DM]/non-DM, 29/23), and 59 had not been treated with them (female/male, 17/42; age, 66.7 ± 14.0 years; number of days of hemodialysis treatment in our clinic, 917 ± 605 [26–2102] days; DM/non-DM, 21/38). During treatment in our clinic, 21 of the 52 patients undergoing antiplatelet therapy experienced a bleeding event (gastrointestinal bleeding 16, brain stem hemorrhage 2, others 3), while 7 of the 59 patients not receiving them had a bleeding event (gastrointestinal bleeding 7) (P

Background Early detection in patients with hypertrophic cardiomyopathy (HCM) is very important. Integrated backscatter (IB) provides a useful noninvasive measure of the acoustic properties of the myocardium, and may detect early myocardial changes. Methods Thirty-four carriers who had gene mutations causing HCM were studied. The patients were divided into three groups as follows: (1) 21 patients with wall hypertrophy (Group A), (2) 7 patients with ECG abnormalities but without wall hypertrophy (Group B), and (3) 6 carriers with neither ECG abnormalities nor wall hypertrophy (Group C). All subjects underwent ECG, conventional echocardiography and acoustic densitometry. In addition, we studied subjects ≤20 years old from Groups B and C (Group B-2 and Group C-2, respectively), and compared them with control subjects with no cardiac disorders who were ≤20 years old. Results In Group A, cyclic variations of integrated backscatter (CV-IB) in the interventricular septum and left ventricular posterior wall were significantly smaller than in Group C. The amplitude of IB in the interventricular septum and left ventricular posterior wall in Group A was significantly higher than those in Group C. Even in Group B, CV-IB in the interventricular septum was significantly smaller than those in Group C. Among patients ≤20 years old, CV-IB in the interventricular septum was significantly smaller in Group B-2 than in control subjects, while that in Group C-2 did not differ from that in control subjects. Conclusions Changes in tissue characterization were found in the hearts of HCM gene carriers even in the absence of wall hypertrophy. These results suggest that tissue changes detectable by the acoustic densitometry methods may occur in the hearts of HCM gene carriers without wall hypertrophy, and that they may be detectable at the time of appearance of ECG abnormalities.

Background PRKAR1A gene encodes the type 1A regulatory subunit of protein kinase A. The mutation of this gene causes Carney complex which is an autosomal dominant multiple neoplasia syndrome characterized by spotty pigmentations, endocrine overactivity and cardiac myxoma. We hypothesized that cardiac myxoma may be associated with PRKAR1A gene mutation and determined whether mutation in the PRKAR1A gene is the cause of familial and sporadic cardiac myxoma. Methods We studied seven patients (three males and four females) with cardiac myxoma. Two of them had familial cardiac myxoma complicated with Carney complex. The other five patients were characterized as sporadic cardiac myxomas. We analyzed the PRKAR1A gene of all patients by the polymerase chain reaction (PCR)–single-strand conformation method, followed with direct sequence analysis. Results We identified a novel mutation (494delTG) in exon 4A of the PRKAR1A gene in the patients with Carney complex. A 16-year-old proband had a left atrial myxoma, pituitary adenoma and skin pigmentation. His father also had left atrial myxoma and skin pigmentation. In contrast, no mutations in the PRKAR1A gene were identified in the other five patients with sporadic cardiac myxomas. Conclusions These results suggest that mutation of the PRKAR1A gene may be associated with familial cardiac myxoma in Carney complex but may not be associated with sporadic cardiac myxoma.

Background: Hypertrophic cardiomyopathy (HCM) is caused by mutations in the genes that encode sarcomeric proteins. Although some patients with HCM have shown dilated cardiomyopathy (DCM)-like features, the relationship between genotype and histologic findings is not well known. Hypothesis: Family members with the same gene mutation may show the same histopathologic changes and clinical manifestations. Methods: Siblings with HCM caused by an Arg92Trp mutation in the cardiac troponin T gene, showing DCM-like features, were examined. Results: The patients were a 69-year-old woman and her 57-year-old brother who both died from congestive heart failure. Their autopsies revealed the same histopathologic findings in the heart. The anterior walls and interventricular septa of their hearts were replaced with extensive fibrosis and showed thinning. Myocyte hypertrophy, disarray, and thickened medial walls of the intramural coronary arteries were found. On electron microscopy, the number of mitochondria was seen to be increased and they formed many clusters. Conclusions: Patients with HCM caused by an Arg92Trp mutation in the cardiac troponin T gene may have the same histopathologic findings, whichmay result in DCM-like features.

Objective: To evaluate the relation between QT variables and disproportion of left ventricular wall hypertrophy in patients with hypertrophic cardiomyopathy. Design: Retrospective analysis of the results of echocardiography and electrocardiography. Setting: University hospital (tertiary referral centre). Patients: 70 patients with hypertrophic cardiomyopathy were divided into four groups according to the distribution of left ventricular wall hypertrophy on cross sectional echocardiography: group A—hypertrophy confined to the interventricular septum; group B—hypertrophy confined to the interventricular septum and left ventricular anterior wall; group C—hypertrophy confined to the interventricular septum, left ventricular anterior wall, and lateral free wall; group D—hypertrophy involving all portions of the left ventricle. Main outcome measures: QT intervals and QT dispersion in precordial six lead ECGs. Results: There were no significant differences in the maximum left ventricular wall thickness among the four groups, and maximum and minimum QTc intervals also did not differ. QTc dispersion was increased significantly in groups A and B compared with groups C and D. Dispersions of the interval from the J point to the end of the T wave (JTc dispersions) in groups A and B were also increased significantly compared with groups C and D. By linear regression analysis, QTc and JTc dispersions correlated with the ratio of the interventricular septal thickness to left ventricular posterior wall thickness (p = 0.0152 and p = 0.0075, respectively). Conclusions: QT dispersion may be affected by not only electrical inhomogeneity but also by morphological inhomogeneity of the left ventricle in patients with hypertrophic cardiomyopathy.

Malignant ventricular tachyarrhythmia (VT) and sudden death are serious events in hypertrophic cardiomyopathy (HCM). However, the pathophysiology of this condition is not well understood. The objective of this study was to evaluate the relationship between cardiac sympathetic nerve activity and the occurrence of VT in HCM patients. Methods and results We studied iodine 123 metaiodobenzylguanidine scintigraphy and 24-hour ambulatory electrocardiographic monitoring in 44 HCM patients, 15 with VT (group A) and 29 without VT (group B). With planar I-123 metaiodobenzylguanidine imaging, the heart-to-mediastinum ratio for early and delayed acquisition and washout rate were calculated. Polar maps of left ventricular myocardium were divided into 20 segments, and the SD of uptake and washout rate in 20 segments were calculated as indices of regional variation. The global washout rate was significantly higher in group A than in group B (26.8 +/- 6.4% vs 17.4 +/- 5.7%, P.0001), although other parameters including heterogeneity indices did not differ. The logistic multiple regression analysis also determined that washout rate was the most powerful predictor of VT in patients with HCM.The occurrence of malignant VT in HCM may be associated with global cardiac sympathetic nerve activity rather than with the heterogeneity of this activity.

KCNQ1 is a gene encoding an α subunit of voltage-gated cardiac K+ channels, with properties similar to the slowly activating delayed rectifier K+ current, and one of the genes causing long QT syndrome (LQTS). However, genotype–phenotype correlations of the KCNQ1 gene mutations are not fully understood. The aims of this study were to identify a mutation in the KCNQ1 gene in patients with LQTS, and to characterize the clinical manifestations and electrophysiological properties of the mutation. We screened and identified mutations by PCR, single-strand conformational polymorphism analysis and DNA sequencing. We identified a novel mutation [Phe193Leu (F193L)] in the KCNQ1 gene in one family with LQTS. The patients with this mutation showed a mildly affected phenotype. The proband was a 17-year-old girl who had a prolonged QT interval. Her elder brother, father and paternal grandmother also had the mutation. None of them had any history of syncope. Sudden death was not found in this family. Next, we studied the electrophysiological characteristics of the F193L mutation in the KCNQ1 gene using the expression system in Xenopus oocytes and the two-microelectrode voltage-clamp technique. Co-expression of F193L KCNQ1 with the K+ channel minK suppressed peak (by 23.3%) and tail (by 38.2%) currents compared with those obtained by the combination of wild-type (WT) KCNQ1 and minK. Time constants of current activation in F193L KCNQ1 and F193L KCNQ1+minK were significantly slower than those of WT KCNQ1 and WT KCNQ1+minK. This electrophysiological study indicates that F193L causes less severe KCNQ1 current suppression, and thereby this mutation may result in a mildly affected phenotype.

ObjectivesWe studied the clinical features of hypertrophic cardiomyopathy (HCM) caused by a novel mutation in the myosin binding protein-C (MyBP-C) gene in patients and family members of Japanese descent.BackgroundPrevious reports have demonstrated that the clinical features of HCM associated with mutations in the MyBP-C gene include late onset and a favorable clinical course. Recently, some mutations in genes encoding sarcomeric proteins have been reported to be a cause of dilated cardiomyopathy (DCM), as well as HCM. However, mutations of the MyBP-C gene have not been reported as a cause of DCM up to now.MethodsWe analyzed MyBP-C gene mutations in 250 unrelated probands with HCM and in 90 with DCM. We used electrocardiography (ECG) and echocardiography to determine clinical phenotypes.ResultsWe identified 17 individuals in 8 families (7 HCM, 1 DCM) with an Arg820Gln mutation in the MyBP-C gene. Overall, 2 (40%) of 5 carriers age >70 years displayed “burnt-out” phase HCM, and one of them had been diagnosed as having DCM before genetic identification. The disease penetrance in subjects age >50 years was 70% by echocardiography and 100% by ECG, and that in those age

Congenital long QT syndrome (LQTS) is caused by mutations in various cardiac potassium or sodium channel genes, with 6 different genotypes thus far identified. However, it is unknown whether these genotypes can be differentiated by QT variables. The electrocardiograms obtained from 16 patients with a mutation in KCNQ1 (LQT1), 7 patients with a mutation in HERG (LQT2) and 20 control subjects were analyzed. The corrected QT interval (QTc), Q-T peak interval (QTpc) and dispersion of QTc or QTpc were measured in 6 precordial leads. The corrected interval from T peak to T end (Tpec) was measured in lead V(5). The maximum QTc, QTc dispersion, and Tpec were significantly increased in the LQT1 and LQT2 patients than in the controls. However, there were no significant differences in these indices between the LQT1 and LQT2 patients. In contrast, QTpc dispersion was significantly increased in the LQT2 patients (78+/-25 ms) compared with the LQT1 patients (29+/-15 ms) and controls (26+/-19 ms). These results suggest that increased lag of the peak of the T wave in each precordial lead (QTpc dispersion) may be a possible index to differentiate LQTS patients with HERG mutation from those with KCNQ1 mutation.

Although cardiovascular disease (CVD) is an important cause of death in patients on hemodialysis, evidence of a beneficial effect of percutaneous intervention (PCI) on stable heart disease is scarce. We investigated the cardiovascular outcomes of hemodialysis patients under our policy of encouraging coronary artery screening tests to the extent possible. A total of 147 hemodialysis patients have been treated in our clinic so far. In 98 of them, coronary artery screening tests were performed, three in unstable and 95 in asymptomatic patients. Significant coronary artery stenosis was detected in 29 at the first tests and in 11 during subsequent tests (40/98, 40.8%), and PCI or coronary artery bypass grafting (CABG) was performed. Multiple PCIs were needed in 21 patients. In the other 49 patients, coronary artery screening tests were not undertaken based on the nephrologist's decision or patient refusal. At the end of the study, 73 (74.5%) patients with tests, and 14 (28.6%) without tests were still outpatients (P0.01). Of 40 patients transferred to other hospitals for medical reasons or who died before transfer, there was cerebrovascular accident in eight, malignancy in six, congestive heart failure without CVD in four, infection in three, sudden cardiac death in one, and others 18. No patient with tests died of CVD and the only patient who died of sudden cardiac death probably due to myocardial infarction was a patient who had declined the screening tests. Coronary artery screening tests, intervention and subsequent periodic tests for asymptomatic hemodialysis patients can reduce the occurrence of cardiovascular events in this population.

A 78-year-old man with unstable angina showed 90 % stenosis in the proximal left anterior descending artery. Pre-procedural intravascular ultrasound revealed ruptured plaque and attenuated plaque in the lesion. Under these conditions, two overlapping sirolimus-eluting stent (SES) implantation in this lesion resulted in slow flow which was recovered by intracoronary nitrates, nicorandil, and nitroprusside without further complications. When the patient showed up again 5 years later with recurrence of angina pectoris, angiography revealed a hazy ulcerated in-stent restenosis (ISR) at the site of the SES. Pre-procedural optical coherence tomography (OCT) imaging revealed multiple intimal ruptures, cavity formation behind the stent struts, a thin-cap fibroatheroma containing neointima surrounded by signal-poor, lipid-rich area in the proximal SES, suggesting the progression of neoatherosclerosis within SES. Importantly, there occurred slow flow again after balloon angioplasty for this lesion. We would suggest careful OCT examination is warranted to confirm development of neoatherosclerosis within the stent, and distal protection device should be considered to prevent slow flow phenomenon even in a patient with very late ISR.

(18)F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) is assumed to be the most useful method for evaluating the viability of the myocardium. However, there are few reports regarding serial changes in (18)F-FDG-PET images of acute myocardial infarction (AMI). We evaluated serial changes in glucose-loaded (18)F-FDG-PET, (123)I-β-methyl-p-iodophenyl-penta-decanoic acid (BMIPP) single-photon emission computed tomography (SPECT) and (99m)Tc-Tetrofosmin (TF) gated SPECT images in patients with AMI.We enrolled 7 consecutive patients with first anterior AMI who successfully underwent percutaneous coronary intervention (PCI). (18)F-FDG-PET images were obtained in the acute, subacute, chronic, mid-term and long-term phases. (123)I-BMIPP and (99m)Tc-TF SPECT images were obtained in the subacute, chronic, mid-term and long-term phases. We determined the total defect score (TDS) for each image. The TDS of the glucose-loaded (18)F-FDG-PET, (123)I-BMIPP and( 99m)Tc-TF SPECT images indicated significant serial decrease (P0.001). Comparing these images, the TDS of the glucose-loaded (18)F-FDG-PET images was larger than that of the (123)I-BMIPP and (99m)Tc-TF SPECT images, and the TDS indicated (18)F-FDG-PET(123)I-BMIPP(99m)Tc-TF in all phases.The defect areas of glucose-loaded (18)F-FDG-PET images were significantly larger than those of (123)I-BMIPP and( 99m)Tc-TF SPECT images during 9 months follow-up of patients with successful PCI for anterior AMI. Additionally, the impairment of glucose metabolism was prolonged.

Although antiplatelet medication is used in various situations, including for the prevention of ischemic and thrombotic complications, long-term antiplatelet therapy in hemodialysis patients who are at high risk of bleeding may result in a harmful bleeding tendency. We investigated bleeding events that required the cessation of the use of heparin for hemodialysis in all the hemodialysis patients treated in our clinic. This analysis revealed 111 patients, of whom 52 had been treated with antiplatelet agents (female/male, 15/37; age, 70.4±11.3years; number of days of hemodialysis treatment in our clinic, 1073±696 [31-2144]days; diabetes mellitus [DM]/non-DM, 29/23), and 59 had not been treated with them (female/male, 17/42; age, 66.7±14.0 years; number of days of hemodialysis treatment in our clinic, 917±605 [26-2102]days; DM/non-DM, 21/38). During treatment in our clinic, 21 of the 52 patients undergoing antiplatelet therapy experienced a bleeding event (gastrointestinal bleeding 16, brain stem hemorrhage 2, others 3), while 7 of the 59 patients not receiving them had a bleeding event (gastrointestinal bleeding 7) (P0.001). Of note, diabetic patients on antiplatelet therapy had the highest incidence of bleeding events (13 of 29 patients; 44.8%), followed by non-diabetic patients on antiplatelet therapy (7 of 23 patients; 30.4%), diabetic patients not receiving antiplatelets (3 of 21 patients; 14.3%), and finally non-diabetic patients not on antiplatelets (4 of 38 patients; 10.5%). Among the patients on antiplatelet therapy, no correlations were apparent between bleeding events and the duration of such therapy or the number of agents. In conclusion, antiplatelet medications can induce bleeding events more frequently in hemodialysis patients, especially in those with DM, than in non-hemodialysis patients, and such agents should be given only under prudent consideration of the associated risks and benefits.

SummaryBackgroundUpper arm swelling and venous hypertension at arteriovenous fistula sites, and insufficiency of hemodialysis are induced by central venous lesions in chronic hemodialysis patients. Percutaneous transluminal angioplasty (PTA) for central venous lesions is first-choice treatment. Cardiac function can be evaluated by measuring the acute increase in venous return volume after PTA.MethodsWe studied 6 cases of successful PTA for central venous stenotic or occluded lesions, and evaluated cardiac function by Swan-Ganz (SG) catheter and ultrasound echocardiography (UCG) at pre-, post-PTA, and on the following day.ResultsEjection fraction (EF) in 6 cases was 71.0±5.5% on UCG. Two cases of subclavian venous stenosis, one case of subclavian venous occlusion, and three cases of brachiocephalic venous occlusion were enrolled. The reference diameter (RD) was 10.2±4.9mm, % diameter-stenosis (%DS) was 92.2±12.2% at pre-PTA, and %DS at post-PTA was 21.7±20.7%. There were no significant differences in pulmonary capillary-wedge, pulmonary artery, and right ventricular end-diastolic pressure in SG at pre- and post-PTA. The pressure of right atrium (RA) and cardiac output (CO) were significantly increased by PTA (RA pressure at pre-/post-PTA, 9.7±2.9/11.7±3.6mmHg, p

The restenosis rate of coronary stent has significantly decreased by implantation of the drug-eluting stent (DES). We often experienced the DES implantation for very small target vessels. The minimum size of DES in Japan and USA is 2.5 mm-diameter, but there were no reports of the expandability of DESs for the very small target vessels with reference diameter

Objectives: The aim of this study was to evaluate the safety and effectiveness of a 0.010-inch guidewire and a balloon catheter for treatment of chronic total occlusion (CTO). Background: Pathological studies have shown that 60–70% of CTO lesions have microchannels of sizes equal to or less than 0.010 inch. Methods: The PIKACHU registry is a prospective, multicenter registry study. A 0.010-inch guidewire had to be used as the first guidewire to attempt to pass the CTO lesion. The primary endpoint was device success using a 0.010 system. Results: A total of 141 patients with 141 lesions were enrolled. The median duration of occlusion was 9 months (range 3–156). Average guiding catheter size was 5.8 ± 0.7 Fr. and TRI was 76.6 %. CTOs were mostly between 10–20 mm long, observed in 53 occlusions. There were 107 lesions (75.9%) with bending of more than 45 degrees. Calcification was seen in 91 lesions (64.5%). A 0.010-inch guidewire was successfully passed through in 97 of 141 lesions (68.8%). A 0.010-inch guidewire compatible balloon catheter was passed in 87 of the 97 lesions (88.7%) and final PCI success was achieved in all the cases. The overall clinical success rate was 87.9% (124/141). No MACE or bleeding complications were observed. Conclusion: The PIKACHU registry data suggest that the 0.010-inch system is safe and practicable for treatment of CTO lesions. © 2010 Wiley-Liss, Inc.

We report regression of the abnormal Q waves of an inferior old myocardial infarction after an additional anterior acute myocardial infarction, and demonstrate the scintigraphic correlation and chronological course of this phenomenon. Scintigraphic findings in the present case here may contribute to an interpretation of regression of abnormal Q waves in myocardial infarction.

A 55-year-old woman was admitted to our hospital because of congestive heart failure despite full medical therapy. She had been diagnosed as having and was treated for cardiomyopathy of unknown cause during an extended period. She had no familial history of cardiovascular diseases or sudden cardiac death. Echocardiograms revealed severely reduced left ventricular (LV) contraction, severe mitral regurgitation, thickened myocardium with prominent trabeculations, and …

Background— The STA gene encodes emerin and is one of the genes that is affected in Emery-Dreifuss muscular dystrophy (EDMD). Although it has been reported that EDMD caused by the STA gene mutation is associated with X-linked recessive inheritance, the genotype-phenotype correlations, with special reference to cardiac manifestations, are not well defined. Methods and Results— We identified 16 carriers (7 male and 9 female) with a nonsense mutation in exon 6 of the STA gene in 2 EDMD families. Pacemakers were required for treatment of bradyarrhythmias in all 7 male carriers and in 2 of the 9 female carriers. In addition, 2 of the 9 female carriers displayed atrial fibrillation. In these 2 families, 3 males without pacemaker implantation, who were not tested genetically, had died suddenly. In these family members, the majority of carriers with the mutation had not been clinically diagnosed as having EDMD before genetic testing because of extremely mild or nonexistent skeletal myopathy. Conclusions— EDMD caused by this mutation is characterized by atypical clinical features and incomplete penetrance of the clinical phenotype and may result in serious cardiac complications, including sudden death. Approaches to preventing possible sudden death in carriers with the STA gene mutation require further study.

金沢大学大学院医学系研究科, Background: There has not been a comparison of the electrocardiographic (ECG) finding of ST-segment elevation in the precordial leads in patients with takotsubo cardiomyopathy (TC) and those with anterior acute myocardial infarction (AMI), with regard to the location of the culprit lesion. Methods and Results: The present study evaluated 18 patients with TC, and 85 with anterior AMI who were divided into 3 groups: group A had the culprit lesion proximal to both the first septal branch (S1) and the first diagonal branch (D1), group B had the culprit lesion proximal to either S1 or D1, and group C had the culprit lesion distal to both S1 and D1. In patients with TC, reciprocal ST-segment depression in the inferior leads was observed less frequently than in patients in groups A (p

LQTS (long QT syndrome) is an inherited cardiac disorder characterized by prolongation of QT interval, torsades de pointes and sudden death. We have identified two heterozygous missense mutations in the KCNQ1 and KCNH2 (also known as HERG) genes [Asp611→Tyr (D611Y) in KCNQ1 and Asp609→Gly (D609G) in KCNH2] in a 2-year-old boy with LQTS. The aim of the present study was to characterize the contributions of the mutations in the KCNQ1 and KCNH2 genes relative to the clinical manifestations and electrophysiological properties of LQTS. Six of 11 carriers of D611Y in KCNQ1 had long QT intervals. D609G in KCNH2 was detected only in the proband. Studies on the electrophysiological alterations due to the two missense mutations revealed that the D611Y mutation in KCNQ1 did not show a significant suppression of the currents compared with wild-type, but the time constants of current activation in the mutants were increased compared with that in the wild-type. In contrast, the D609G mutation in KCNH2 showed a dominant-negative suppression. Our results suggest that the mild phenotype produced by the D611Y mutation in KCNQ1 became more serious by addition of the D609G mutation in KCNH2 in the proband.

Patients with LQTS (long QT syndrome) with a mutation in a cardiac ion channel gene, leading to mild-to-moderate channel dysfunction, may manifest marked QT prolongation or torsade de pointes only upon an additional stressor. A 59-year-old woman had marked QT prolongation and repeated torsade de pointes 3 months after initiation of probucol, a cholesterol-lowering drug. We identified a single base substitution in the HERG gene by genetic analysis. This novel missense mutation is predicted to cause an amino acid substitution of Met124→Thr (M124T) in the N-terminus. Three other relatives with this mutation also had QT prolongation and one of them had a prolonged QT interval and torsade de pointes accompanied by syncope after taking probucol. We expressed wild-type HERG and HERG with M124T in Xenopus oocytes and characterized the electrophysiological properties of these HERG channels and the action of probucol on the channels. Injection of the M124T mutant cRNA into Xenopus oocytes resulted in expression of functional channels with markedly smaller amplitude. In both HERG channels, probucol decreased the amplitude of the HERG tail current, decelerated the rate of channel activation, accelerated the rate of channel deactivation and shifted the reversal potential to a more positive value. The electrophysiological study indicated that QT lengthening and cardiac arrhythmia in the two present patients were due to inhibition of IKr (rapidly activating delayed rectifier K+ current) by probucol, in addition to the significant suppression of HERG current in HERG channels with the M124T mutation.

Left ventricular (LV) systolic function in hypertrophic cardiomyopathy (HCM) is usually normal. Late in the disease, however, LV systolic dysfunction and dilatation are recognized. Although abnormalities in cardiac sympathetic nerve activity in patients with HCM have been demonstrated using (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, the changes of cardiac sympathetic nerve activity throughout the clinical course from typical to end-stage HCM are unclear. The objective of this study was to evaluate the relationship between abnormalities on (123)I-MIBG myocardial scintigraphy and pathophysiologic changes in patients with HCM.We performed (123)I-MIBG scintigraphy on 46 patients with HCM and 18 age-matched control subjects. The patients were categorized into 3 groups: 28 patients with normal LV systolic function (group A), 9 patients with LV systolic dysfunction (group B), and 9 patients with LV systolic dysfunction and dilatation (group C). With planar (123)I-MIBG imaging, the heart-to-mediastinum ratio for early and delayed acquisitions and the washout rate were calculated. With SPECT, polar maps of the LV myocardium were divided into 20 segments. The regional uptake and washout rate were calculated from semiquantitative 20-segment bull's-eye analysis.The early uptake was significantly lower in group C than in the control group (P0.01). The washout rate was progressively higher in group A, group B, and group C (P0.01). Reduced regional early uptake was found in 2.9 +/- 3.4 (group A), 4.1 +/- 4.7 (group B), and 7.4 +/- 4.3 (group C) segments, respectively. In group C, regional early uptake was significantly reduced, predominantly in the interventricular septal wall, and regional washout rate was increased in the apex and lateral wall.These results suggest that cardiac sympathetic nerve abnormalities in patients with HCM may advance with development of LV systolic dysfunction and dilatation and that (123)I-MIBG myocardial scintigraphy may be a useful tool for the evaluation of pathophysiologic changes in HCM.

QT dispersion (QTD) on 12-lead ECGs has been proposed as a marker of malignant ventricular tachyarrhythmias, and increased QTD has been reported in long QT syndrome (LQTS). On the other hand, it has been demonstrated that transmural dispersion is associated with ventricular tachyarrhythmias in an experimental model. However, the precise type of QTD or transmural dispersion that contributes most to ventricular tachyarrhythmias in patients with LQTS remains unclear. We evaluated 27 patients with acquired LQTS. These patients were divided into two groups: group A (n=12), patients with polymorphic ventricular tachycardia [torsades de pointes (TdP)], and group B (n=15), patients without TdP. The QT intervals were corrected using Bazett's formula. QTD was measured as the difference between the maximum and the minimum QT intervals, and T wave peak-to-end interval divided by the QT interval (Tpe) in the V5 lead was measured as a new index. Both the corrected QTD (QTDc) and Tpe were significantly larger in group A than in group B. Logistic regression analysis revealed that a reliable predictor for TdP in the QT variables in these patients was not QTDc but Tpe. Cumulative frequency distributions revealed that a Tpe of 0.28 is a good cut-off point for TdP. Tpe did not correlate with the corrected maximum QT interval, whereas the QTDc did correlate with this parameter. In conclusion, Tpe may be the best predictor for TdP in patients with acquired LQTS.

Congenital long QT syndrome (LQTS) is caused by mutations in various cardiac potassium or sodium channel genes, with 6 different genotypes thus far identified. However, it is unknown whether these genotypes can be differentiated by QT variables. The electrocardiograms obtained from 16 patients with a mutation in KCNQ1 (LQT1), 7 patients with a mutation in HERG (LQT2) and 20 control subjects were analyzed. The corrected QT interval (QTc), Q-T peak interval (QTpc) and dispersion of QTc or QTpc were measured in 6 precordial leads. The corrected interval from T peak to T end (Tpec) was measured in lead V(5). The maximum QTc, QTc dispersion, and Tpec were significantly increased in the LQT1 and LQT2 patients than in the controls. However, there were no significant differences in these indices between the LQT1 and LQT2 patients. In contrast, QTpc dispersion was significantly increased in the LQT2 patients (78+/-25 ms) compared with the LQT1 patients (29+/-15 ms) and controls (26+/-19 ms). These results suggest that increased lag of the peak of the T wave in each precordial lead (QTpc dispersion) may be a possible index to differentiate LQTS patients with HERG mutation from those with KCNQ1 mutation.