Association between left atrial low-voltage area and induction and recurrence of macroreentrant atrial tachycardia in pulmonary vein isolation for atrial fibrillation.

BACKGROUND: The relationship between induction and recurrence due to atrial tachycardia (AT) and left atrial (LA) matrix progression after atrial fibrillation (AF) ablation remains unclear. METHODS: One hundred fifty-two consecutive patients with paroxysmal and persistent AF who underwent pulmonary vein isolation (PVI) and cavo-tricuspid isthmus (CTI) ablation and achieved sinus rhythm before the procedure were classified into three groups according to the AT pattern induced after the procedure: group N (non-induced), F (focal pattern), and M (macroreentrant pattern) in 3D mapping. RESULTS: The total rate of AT induction was 19.7% (30/152) in groups F (n = 13) and M (n = 17). Patients in group M were older than those in groups N and F, with higher CHADS2/CHA2DS2-VASc values, left atrial enlargement, and low-voltage area (LVA) size of LA. The receiver operating characteristic curve determined that the cut-off LVA for macroreentrant AT induction was 8.8 cm2 (area under the curve [AUC]: 0.86, 95% confidence interval [CI]: 0.75-0.97). The recurrence of AT at 36 months in group N was 4.1% (5/122), and at the second ablation, all patients had macroreentrant AT. Patients with AT recurrence in group N had a wide LVA at the first ablation, and the cut-off LVA for AT recurrence was 6.5 cm2 (AUC 0.94, 95%CI 0.88-0.99). Adjusted multivariate analysis showed that only LVA size was associated with the recurrence of macroreentrant AT (odds ratio 1.21, 95%CI 1.04-1.51). CONCLUSIONS: It is important to develop a therapeutic strategy based on the LVA size to suppress the recurrence of AT in these patients.

Midterm Clinical Outcomes for Deferred Coronary Revascularization on the Basis of Resting Full-Cycle Ratio and Fractional Flow Reserve Measurements.

The midterm prognosis of patients with deferred revascularization based on resting full-cycle ratio (RFR) or fractional flow reserve (FFR) is not well established. We investigated the midterm clinical outcomes of 137 consecutive patients with deferred revascularization of 177 coronary arteries based on RFR and FFR. Patients were classified into 3 groups (concordant normal, concordant abnormal, discordant FFR and RFR), using known cutoffs for FFR (≤0.80) and RFR (≤0.89). All-cause mortality occurred in 9 (6.6%) and major adverse cardiac events (MACEs) in 16 patients (11.7%). Concordant abnormal, age, body mass index (BMI), and current or history of cancer were associated with increased risks of all-cause mortality. In a multivariable model, current or history of cancer was significantly associated with all-cause death (hazard ratio [HR] 6.8, p = 0.02). Concordant abnormal, current or history of cancer, BMI, and left ventricular ejection fraction were associated with increased risk of MACE, and all predictors correlated significantly with MACE (abnormal concordance: HR 4.2, p = 0.043; current or history of cancer: HR 4.0, p = 0.047; BMI: HR 0.8, p = 0.020; left ventricular ejection fraction: HR 0.9, p = 0.017). Although these results support performing percutaneous coronary intervention according to evidence-based RFR or FFR thresholds, deferred lesions with discordant FFR and RFR results were not associated with worse prognosis.

RR interval variability in the evaluation of ventricular tachycardia and effects of implantable cardioverter defibrillator therapy.

BACKGROUND: An implantable cardioverter defibrillator (ICD) is the most reliable therapeutic device for preventing sudden cardiac death in patients with sustained ventricular tachycardia (VT). Regarding its effectiveness, targeted VT is defined based on the tachyarrhythmia cycle length. However, variations in RR interval variability of VTs may occur. Few studies have reported on VT characteristics and effects of ICD therapy according to the RR interval variability. We aimed to identify the clinical characteristics of VTs and ICD therapy effects according to the RR interval variability. METHODS: We analyzed 821 VT episodes in 69 patients with ICDs or cardiac resynchronization therapy defibrillators. VTs were classified as irregular when the difference between two successive beats was >20 ms in at least one of 10 RR intervals; otherwise, they were classified as regular. We evaluated successful termination using anti-tachycardia pacing (ATP)/shock therapy, spontaneous termination, and acceleration between regular and irregular VTs. The RR interval variability reproducibility rates were evaluated. RESULTS: Regular VT was significantly more successfully terminated than irregular VT by ATP. No significant difference was found in shock therapy or VT acceleration between the regular and irregular VTs. Spontaneous termination occurred significantly more often in irregular than in regular VT cases. The reproducibility rates of RR interval variability in each episode and in all episodes were 89% and 73%, respectively. CONCLUSIONS: ATP therapy showed greater effectiveness for regular than for irregular VT. Spontaneous termination was more common in irregular than in regular VT. RR interval variability of VTs seems to be reproducible.

Relationship between resting full-cycle ratio and fractional flow reserve in assessments of coronary stenosis severity.

AIM: Comparisons between the resting full-cycle ratio (RFR), a new physiological resting index, and fractional flow reserve (FFR) in terms of prognostic value are limited. We aimed to identify the prognostic value of concordance between RFR and FFR and to determine the stability of measured RFR. METHODS AND RESULTS: We measured FFR and RFR in 161 coronary arteries of 119 patients and classified the data using known cutoffs for FFR (≤0.80) and RFR (≤0.89) into groups; high FFR and high RFR (high FFR/low RFR) group, high FFR and low RFR (high FFR/low RFR) group, low FFR and high RFR (low FFR/high RFR) group, and low FFR and low RFR (low FFR/low RFR) group. The concordance rates in these groups were 42.2% (68/161), 4.4% (7/161), 14.3% (23/161), and 39.1% (63/161), respectively. The concordance between FFR and RFR was 81.4%. The prevalence of females was significantly higher, values for hemoglobin values were significantly lower, and average E/E' (an index of left ventricular (LV) diastolic function by echocardiography) was significantly higher in high FFR/low RFR group than in low FFR/high RFR group (p = .008, .050, and .028, respectively). CONCLUSIONS: The RFR and FFR values consistently agreed. Female, anemia, and LV diastolic dysfunction may be related to the difference of discordance between high FFR/low RFR and low FFR/high RFR.

Superior Rhythm Discrimination With the SmartShock Technology Algorithm　- Results of the Implantable Defibrillator With Enhanced Features and Settings for Reduction of Inaccurate Detection (DEFENSE) Trial.

BACKGROUND: Shocks delivered by implanted anti-tachyarrhythmia devices, even when appropriate, lower the quality of life and survival. The new SmartShock Technology®(SST) discrimination algorithm was developed to prevent the delivery of inappropriate shock. This prospective, multicenter, observational study compared the rate of inaccurate detection of ventricular tachyarrhythmia using the SST vs. a conventional discrimination algorithm.Methods and Results:Recipients of implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy defibrillators (CRT-D) equipped with the SST algorithm were enrolled and followed up every 6 months. The tachycardia detection rate was set at ≥150 beats/min with the SST algorithm. The primary endpoint was the time to first inaccurate detection of ventricular tachycardia (VT) with conventional vs. the SST discrimination algorithm, up to 2 years of follow-up. Between March 2012 and September 2013, 185 patients (mean age, 64.0±14.9 years; men, 74%; secondary prevention indication, 49.5%) were enrolled at 14 Japanese medical centers. Inaccurate detection was observed in 32 patients (17.6%) with the conventional, vs. in 19 patients (10.4%) with the SST algorithm. SST significantly lowered the rate of inaccurate detection by dual chamber devices (HR, 0.50; 95% CI: 0.263-0.950; P=0.034). CONCLUSIONS: Compared with previous algorithms, the SST discrimination algorithm significantly lowered the rate of inaccurate detection of VT in recipients of dual-chamber ICD or CRT-D.

Lead extractions in patients with cardiac implantable electronic device infections: Single center experience.

BACKGROUND: Lead extraction using laser sheaths is performed mainly for cardiac implantable electronic device (CIED) infections. However, there are few reports concerning the management of CIED infections in Japan. METHODS AND RESULTS: Lead extraction procedures were performed in 183 patients targeting 450 leads (atrial leads: 170, ventricular: 181, implantable cardioverter-defibrillators (ICDs): 79, and coronary sinus: 20). One hundred twenty patients (65.6%) presented with pocket infections without the presentation of an endovascular infection. Blood cultures were positive at least once in 63 patients (34.4%). Complete procedure success was achieved for 437 leads (97.1%) while partial removal occurred in nine, and failure in four leads. Major complications directly related to the procedure occurred in five patients (2.7%). Two of the four patients with a cardiac tamponade required a surgical repair. All patients received intravenous antibiotics, at least, one week after the procedure. Pocket or systemic infections were successfully controlled in 181 patients (98.9%). Coagulase-negative staphylococci (30.1%) and Staphylococcus aureus (37.1%) were the most common causes of CIED infections. CONCLUSION: The current status of CIED infections in Japan seems to be similar to that previously reported from foreign countries. The optimal treatment of CIED infections involves the complete explantation of all hardware, followed by antibiotic therapy.

Importance of nonpulmonary vein foci in catheter ablation for paroxysmal atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) isolation is an established treatment strategy for paroxysmal atrial fibrillation (PAF). However, the recurrence rate of PAF is 8% to 37%, despite repeated procedures, and the catheter ablation strategy for PAF with non-PV foci is unclear. OBJECTIVE: The purpose of this study was to assess the PAF ablation strategy for non-PV foci. METHODS: The study included 304 consecutive patients undergoing PAF ablation (209 males, age 63.0 ± 10.4 years) divided into 3 groups: group 1 (245 patients) with no inducible non-PV foci; group 2 (34 patients) with atrial fibrillation (AF) originating from non-PV foci and all the foci successfully ablated; and group 3 (25 patients) with AF originating from non-PV triggers, but without all foci being ablated or with persistently inducible AF. RESULTS: Mean follow-up period was 26.9 ± 11.8 months, and AF recurrence rates since the last procedure were 9.8%, 8.8%, and 68.0% in groups 1, 2, and 3, respectively. There was no statistically significant difference in recurrence rate between groups 1 and 2 (P = .89); however, there were statistically significant differences between groups 3 and 1 (P <.0001) and groups 3 and 2 (P <.0001). The patients in group 2 had an AF-free outcome to equivalent to those who had PV foci in group 1 (P = .83). CONCLUSION: Success rates can be improved for PAF ablation if non-PV foci are detected and eliminated.

Negatively charged low-density lipoprotein is associated with atherogenic risk in hypertensive patients.

Negatively charged low-density lipoprotein (LDL), generated via multiple processes such as oxidation, acetylation, or glycosylation, plays a key role in the initiation and progression of atherosclerosis and related diseases. Anion-exchange high-performance liquid chromatography (AE-HPLC) can subfractionate LDL into LDL-1, LDL-2, and LDL-3 based on LDL particle charge, but the clinical significance of LDL subfractions has not yet been elucidated. The aim of this study was to determine the clinical significance of these fractions with particular regard to atherogenic risk in hypertensive patients. Ninety-eight patients with essential hypertension (age 67.0 ± 10.7 years; 54 males) were enrolled in the present study. The relationships between LDL subfractions and atherogenic risk factors, including lipid profiles, blood pressure and plasma 8-isoprostane as a marker of oxidative stress, were examined. LDL-1 levels were significantly and negatively correlated with body mass index (r = -0.384, p < 0.001), systolic blood pressure (r = -0.457, p < 0.001), non-high-density lipoprotein cholesterol levels (r = -0.457, p < 0.001) and 8-isoprostane levels (r = -0.415, p < 0.001). LDL-3, which is the most negatively charged fraction of total LDL, was significantly and positively correlated with these parameters (r = 0.267, 0.481, 0.357, and 0.337, respectively). LDL-1 levels were significantly lower (p < 0.001), and LDL-2 and LDL-3 levels were significantly higher (each p < 0.001) in patients with poorly controlled hypertension than in patients with well-controlled hypertension. In addition, an increase in the total number of traditional risk factors at time of study participation, but not previous diagnosis, was associated with a decrease in LDL-1 levels and increases in LDL-2 and LDL-3 levels. These data suggest that LDL subfractions are associated with multiple atherogenic risk factors and that treatment to modify these risk factors could result in changes in LDL subfraction levels. In conclusion, LDL subfractions isolated by AE-HPLC may represent a marker of atherogenic risk in patients with hypertension.

Chest pain and ST segment depression caused by expansion of gastric tube used for esophageal reconstruction.

We describe a 76-year-old man in whom a gastric tube was used for esophageal reconstruction via the anterior mediastinum after esophagectomy for esophageal cancer. Stenosis of the tube resulted in fluid accumulation, which directly compressed the heart and caused angina-like chest pain associated with ST-segment depression in lead V(2-3) on the electrocardiogram (ECG). Coronary angiography revealed no stenosis. Drainage of the fluid in the gastric tube resulted in immediate relief of symptoms and normalization of ECG. Angina-like chest pain associated with ST segment changes were caused by expansion of the gastric tube and compression of the heart.

Evaluation of venous thromboembolism and coagulation-fibrinolysis markers in Japanese patients with inflammatory bowel disease.

BACKGROUND: Arterial or venous thromboembolism is rarely encountered clinically as an extradigestive tract complication in inflammatory bowel disease (IBD). However, it is one of the important prognostic factors for IBD patients. The present study was designed to evaluate the relationship between pulmonary embolism (PE) and deep vein thrombosis (DVT) with coagulation-fibrinolysis markers in patients with active IBD. METHODS: In 47 consecutive cases hospitalized due to active IBD [26 with Crohn's disease (CD) and 21 with ulcerative colitis (UC)], we evaluated the disease severity, blood tests, pulmonary ventilation-perfusion scan (V/Q scan), and magnetic resonance venography (MRV) or conventional venography. RESULTS: PE was diagnosed by V/Q scan in 5 (2 with CD and 3 with UC; 10.6%). DVT was diagnosed in 5 (2 with CD and 3 with UC; 10.6%). Of the 47 patients, 8 (17.0%) had venous thromboembolism (either PE or DVT), and 2 of them (4.3%) had both conditions. In UC patients, the thrombosis group was in more severe stages based on endoscopic grading than the nonthrombosis group. In all patients, the thrombosis group were older (50.3 +/- 14.3 years) than the nonthrombosis group (29.2 +/- 11.7 years). Furthermore, the thrombosis group had higher thrombin-antithrombin III complex (13.1 +/- 17.7 ng/ml) and d-dimer (964 +/- 1402 ng/ml) values than the nonthrombosis group (5.3 +/- 5.5 ng/ml, P=0.0245, and 207 +/- 192 ng/ml, P=0.0016, respectively). There were no significant differences in leukocyte and platelet counts, C-reactive protein, and fibrinogen between the two groups. CONCLUSIONS: A high incidence of venous thromboembolism was suggested in Japanese patients with active IBD. We should be careful with thrombosis in treatment of IBD patients, especially those who are of older age and in more severe stages.

The use of a hydrophilic-coated catheter during transradial cardiac catheterization is associated with a low incidence of radial artery spasm.

BACKGROUND: Radial artery spasm (RAS) is a common complication of transradial approach (TRA) to percutaneous coronary angiography (CAG) and coronary intervention. Lower friction resistance between catheter and RA wall may reduce RAS upon insertion, manipulation, and withdrawal of the catheter. The aim of this study was to investigate whether the use of a hydrophilic-coated (HC) catheter, which has lower friction coefficient, could reduce the incidence of RAS compared with a non-hydrophilic-coated (NHC) catheter. METHODS: A total 250 patients attempted diagnostic CAG using 5-French catheters via the TRA between September 2000 and April 2002. Two hundred thirty-four (93.6%) patients who achieved successful coronary cannulation were selected for the study. NHC catheters were used in 149 patients (63.7%), and HC catheters were used in 85 patients (36.3%). We compared the incidence of RAS between NHC and HC catheters. RESULTS: RAS occurred in 17 (7%) patients totally. RAS was less likely to occur in HC group (one patient, 1%) than in the NHC group (16 patients, 11%, P = 0.007). CONCLUSIONS: We conclude that the use of HC catheters can reduce RAS upon insertion, manipulation, and withdrawal of the catheter compared with NHC catheters.

Successful treatment of chronic pulmonary thromboembolism by long-term intermittent administration of milrinone, a phosphodiesterase-ill inhibitor.

We report a 71-year-old man with right heart failure due to chronic pulmonary thromboembolism. Oral medications failed to control the condition but he was later successfully treated with intermittent administration of a PDE-III inhibitor for 2 years. Such therapy did not result in exacerbation of right heart failure but improvement of ANP/BNP levels to 32/104 pg/ml from a pretreatment value of 61/158 pg/ml, although no improvement was noted in pulmonary artery pressure or cardiac index. Intermittent administration of PDE-III inhibitors is a useful treatment for patients with right heart failure resistant to oral agents.