Shigeki Kimura

Long-Term Follow-Up after Catheter Ablation of Paroxysmal Atrial Fibrillation: The Incidence of Recurrence and Progression of Atrial Fibrillation

Background— Although catheter ablation (CA) is a standard treatment for atrial fibrillation (AF), its long-term efficacy remains unclear. This study aimed to elucidate the incidences of AF recurrence and of progression from paroxysmal to persistent AF, after CA, in patients with paroxysmal AF. Methods and Results— We examined the incidence of AF recurrence and AF progression in 1220 consecutive patients (mean age, 61 years), with symptomatic paroxysmal AF, undergoing CA, based on extensive pulmonary vein isolation and focal ablation for nonpulmonary vein foci. AF recurrence–free survival probabilities at 5 years were 59.4% after the initial CA and 81.1% after the final CA (average, 1.3 procedures). During a median follow-up period of 47.9 (range, 5.3–123.3) months after the initial CA, AF progressed from paroxysmal to persistent in 15 (1.2%) patients (0.3%/y). The duration of AF history (hazard ratio [HR], 1.03; P <0.0001), number of ineffective antiarrhythmics (HR, 1.09; P =0.005), and left atrial diameter indexed by the body surface area (HR, 1.05; P =0.001) were significant predictors of AF recurrence. Patient age (HR, 1.12; P =0.0001) and left atrial diameter indexed by the body surface area (HR, 1.26; P =0.0006) were significantly associated with AF progression. Patients aged ≤65 years and with a left atrial diameter indexed by the body surface area of ≤24.0 mm/m2 did not develop AF progression for ≤10 years after the initial CA. Conclusions— Although the long-term follow-up revealed the effect of CA on preventing AF recurrence, repeated CA sessions might be required. The rate of progression from paroxysmal to persistent AF was 0.3%/y.Background—Although catheter ablation (CA) is a standard treatment for atrial fibrillation (AF), its long-term efficacy remains unclear. This study aimed to elucidate the incidences of AF recurrence and of progression from paroxysmal to persistent AF, after CA, in patients with paroxysmal AF. Methods and Results—We examined the incidence of AF recurrence and AF progression in 1220 consecutive patients (mean age, 61 years), with symptomatic paroxysmal AF, undergoing CA, based on extensive pulmonary vein isolation and focal ablation for nonpulmonary vein foci. AF recurrence–free survival probabilities at 5 years were 59.4% after the initial CA and 81.1% after the final CA (average, 1.3 procedures). During a median follow-up period of 47.9 (range, 5.3–123.3) months after the initial CA, AF progressed from paroxysmal to persistent in 15 (1.2%) patients (0.3%/y). The duration of AF history (hazard ratio [HR], 1.03; P<0.0001), number of ineffective antiarrhythmics (HR, 1.09; P=0.005), and left atrial diameter indexed by the body surface area (HR, 1.05; P=0.001) were significant predictors of AF recurrence. Patient age (HR, 1.12; P=0.0001) and left atrial diameter indexed by the body surface area (HR, 1.26; P=0.0006) were significantly associated with AF progression. Patients aged ⩽65 years and with a left atrial diameter indexed by the body surface area of ⩽24.0 mm/m2 did not develop AF progression for ⩽10 years after the initial CA. Conclusions—Although the long-term follow-up revealed the effect of CA on preventing AF recurrence, repeated CA sessions might be required. The rate of progression from paroxysmal to persistent AF was 0.3%/y.

Clinical Significance of Echo Signal Attenuation on Intravascular Ultrasound in Patients With Coronary Artery Disease

Background—Atherosclerotic plaque that shows echo signal attenuation (EA) without associated bright echoes is sometimes observed by intravascular ultrasound but its clinical significance remains unclear. We investigated the impact of EA on coronary perfusion and evaluated the pathological features of plaque with EA. Methods and Results—We studied 687 native coronary lesions in 687 consecutive patients (336 with acute coronary syndrome and 351 with stable angina pectoris) who underwent intravascular ultrasound before percutaneous coronary intervention. By subgroup analysis, 60 lesions (30 lesions with EA) treated with directional coronary atherectomy underwent pathological examination. The Thrombolysis in Myocardial Infarction (TIMI) flow grade and myocardial blush grade after percutaneous coronary intervention were compared between lesions with and without EA in 627 lesions except directional coronary atherectomy subgroup. EA was observed in 245 lesions (35.7%), and coronary flow after percutaneous coronary intervention was worse for lesions with EA than without (final TIMI grade of 0 to 2: 15.4% versus 2.4%, P<0.001; final myocardial blush grade of 0 to 2: 45.6% versus 21.4%, P<0.001). Multivariate analysis revealed a significant association between no reflow (TIMI grade 0 to 2) and EA (odds ratio, 5.59; 95% CI, 2.64 to 11.85; P<0.001), a baseline TIMI grade of 0 to 2 (odds ratio, 5.91; 95% CI, 2.79 to 12.5; P<0.001), and a large reference area (odds ratio, 3.08; 95% CI, 1.40 to 6.76; P=0.005) after controlling for other associated factors. Pathological examination revealed a significantly higher frequency of lipid-rich plaque with microcalcification in lesions with EA. Conclusions—Atherosclerotic plaque with EA showed a significant association with no reflow after percutaneous coronary intervention, suggesting the existence of fragile components susceptible to distal embolization.

Differences in catheter ablation of paroxysmal atrial fibrillation between males and females

BACKGROUND Catheter ablation (CA) has become a standard treatment for patients with atrial fibrillation (AF). However, gender-related differences associated with CA of paroxysmal AF (PAF) remain unclear. METHODS We compared 1124 consecutive patients (mean age, 61 ± 10 years; male, n=864) with PAF scheduled for CA between the genders. RESULTS Females were significantly older (p<0.0001), and had a lower body-mass-index (p=0.02), smaller left atrial dimension (LAD; p=0.04), larger LAD indexed by the body-surface-area (LADI; p<0.0001) and better left ventricular ejection fraction (p<0.0001) at baseline. Ischemic heart disease (p=0.007) was more frequent in males, whereas hypertrophic cardiomyopathy (p=0.007) and mitral stenosis (p=0.001) were more frequent in females. More additional procedures were performed to eliminate non-pulmonary vein foci in females than males (p<0.05), but those locations were similar between the genders. The incidence of procedure-related complications was similar between genders (p=0.73). Sinus rhythm was similarly maintained between females and males after the first CA (56.4% vs. 59.3% at 5 years, p=0.24), but was significantly lower in females after the last CA (76.5% vs. 81.3% at 5 years, p=0.007). More females did refuse multiple CA procedures (especially a second one) than males (37.8% in females vs. 27.4% in males, p=0.02). The age (HR, 0.98/y, p=0.01), duration of AF (HR, 1.04/y, p=0.0001), number of failed anti-arrhythmic-drugs (HR, 1.10, p=0.03) and LADI (HR, 1.89 per 10mm/m(2), p=0.001) were significantly associated with AF-recurrence in males, but not in females. CONCLUSIONS Specific differences and similarities between the genders were observed in PAF patients undergoing CA.

Quantitative assessment of tissue prolapse on optical coherence tomography and its relation to underlying plaque morphologies and clinical outcome in patients with elective stent implantation.

BACKGROUND Tissue prolapse (TP) is sometimes observed after percutaneous coronary intervention (PCI), but its clinical significance remains unclear. We investigated the relationship between TP volume on optical coherence tomography (OCT) after PCI and underlying plaque morphologies and the impact of TP on clinical outcomes. METHODS We investigated 178 native coronary lesions with normal pre-PCI creatine kinase-myocardial band (CK-MB) values (154 lesions with stable angina; 24 with unstable angina). TP was defined as tissue extrusion from stent struts throughout the stented segments. All lesions were divided into tertiles according to TP volume. The differences in plaque morphologies and 9-month clinical outcomes were evaluated. RESULTS TP volume was correlated with lipid arc (r=0.374, p<0.0001) and fibrous cap thickness (r=-0.254, p=0.001) at the culprit sites. The frequency of thin-cap fibroatheroma (TCFA) was higher in the largest TP tertile (≥ 1.38 mm(3)) (p=0.015). In multivariate analysis, right coronary artery lesion (odds ratio [OR]: 2.779; p=0.005), lesion length (OR: 1.047; p=0.003), and TCFA (OR: 2.430; p=0.022) were related to the largest TP tertile. Lesions with post-PCI CK-MB elevation (>upper reference limit) had larger TP volume than those without (1.28 [0.48 to 3.97] vs. 0.70 [0.16 to 1.64] mm(3), p=0.007). The prevalence of cardiac events during the 9-month follow-up was not significantly different according to TP volume. CONCLUSIONS TP volume on OCT was related to plaque morphologies and instability, and post-PCI myocardial injury, but not to worse 9-month outcomes.

Association of Intravascular Ultrasound- and Optical Coherence Tomography-Assessed Coronary Plaque Morphology With Periprocedural Myocardial Injury in Patients With Stable Angina Pectoris

BACKGROUND Periprocedural myocardial injury (PMI) is not an uncommon complication and is related to adverse cardiac events after percutaneous coronary intervention (PCI). We investigated the predictors of PMI in patients with stable angina pectoris (SAP) on intravascular imaging. METHODSANDRESULTS We enrolled 193 SAP patients who underwent pre-PCI intravascular ultrasound (IVUS) and optical coherence tomography (OCT). Clinical characteristics, lesion morphology, and long-term follow-up data were compared between patients with and without PMI, defined as post-PCI elevation of high-sensitivity cardiac troponin-T. PMI were observed in 79 patients (40.9%). Estimated glomerular filtration rate (odds ratio [OR], 0.973; 95% confidence interval [CI]: 0.950-0.996; P=0.020), ≥2 stents (OR, 3.100; 95% CI: 1.334-7.205; P=0.009), final myocardial blush grade 0-2 (OR, 4.077; 95% CI: 1.295-12.839; P=0.016), and IVUS-identified echo-attenuated plaque (EA; OR, 3.623; 95% CI: 1.700-7.721; P<0.001) and OCT-derived thin-cap fibroatheroma (OCT-TCFA; OR, 3.406; 95% CI: 1.307-8.872; P=0.012) were independent predictors of PMI on multivariate logistic regression analysis. A combination of EA and OCT-TCFA had an 82.4% positive predictive value for PMI. On Cox proportional hazards analysis, PMI was an independent predictor of adverse cardiac events during 1-year follow-up (hazard ratio, 2.984; 95% CI: 1.209-7.361; P=0.018). CONCLUSIONS Plaque morphology assessment using pre-PCI IVUS and OCT may be useful for predicting PMI in SAP patients.

Efficacy of pressure parameters obtained during contrast medium-induced submaximal hyperemia in the functional assessment of intermediate coronary stenosis

BACKGROUND Despite evidence demonstrating the superiority of percutaneous coronary intervention guided by fractional flow reserve (FFR), FFR evaluation has not been widely adopted. We sought to determine the diagnostic performance of baseline conditions and contrast medium-induced pressure indices in predicting FFR. We hypothesized that the contrast medium-induced end-diastolic pressure parameter would offer superior diagnostic agreement with FFR, compared to other indices. METHODS & RESULTS Ninety-one intermediate stenoses in 75 patients were studied prospectively. The baseline distal coronary pressure to aortic pressure ratio (Pd/Pa) and end-diastolic instantaneous Pd/Pa 60 ms before the electrocardiographic R-wave (ED-Pd/Pa) were measured; then, after intracoronary injection of 6 mL contrast medium at 3 mL/s, Pd/Pa (C-Pd/Pa) and end-diastolic Pd/Pa (C-ED-Pd/Pa) were obtained. Subsequently, conventional FFR was measured as a reference standard. Of the 91 lesions, 11 (12.1%) were excluded because of suboptimal data acquisition, leaving 80 for final analysis. C-ED-Pd/Pa values (median 0.80 [interquartile range 0.70-0.88]) were significantly lower than conventional FFR (0.83 [0.75-0.89], P<0.01), whereas Pd/Pa (0.93 [0.90-0.96], P<0.01), ED-Pd/Pa (0.91 [0.87-0.93], P<0.01), and C-Pd/Pa (0.85 [0.79-0.90], P<0.05) were significantly higher. Correlation coefficients (R) with conventional FFR were 0.74 (standard error of the estimate [SEE] 0.067, P<0.0001), 0.78 (SEE 0.062, P<0.0001), 0.85 (SEE 0.052, P<0.0001), and 0.93 (SEE 0.037, P<0.0001) for Pd/Pa, ED-Pd/Pa, C-Pd/Pa, and C-ED-Pd/Pa, respectively. Diagnostic accuracy was 81.2%, 83.8%, 87.5% and 93.8% for Pd/Pa, ED-Pd/Pa, C-Pd/Pa, and C-ED-Pd/Pa, respectively. CONCLUSIONS Among baseline indices and contrast-induced pressure parameters, C-ED-Pd/Pa is a novel, feasible, and high-performance measure for the physiological assessment of intermediate coronary stenosis.

The prognostic value of the serum eicosapentaenoic acid to arachidonic acid ratio in relation to clinical outcomes after endovascular therapy in patients with peripheral artery disease caused by femoropopliteal artery lesions

BACKGROUND The EPA/AA ratio has emerged as a predictor of mortality endpoints in cardiac disease; however, its prognostic value in peripheral artery disease (PAD) patients is unclear. We assessed the serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio in patients with PAD caused by femoropopliteal artery lesions, to determine whether it predicts clinical outcomes after endovascular therapy (EVT). METHODS AND RESULTS We obtained serum EPA/AA ratios from 132 consecutive patients with PAD caused by femoropopliteal artery lesions before EVT. Patients were divided into two groups using the median value of serum EPA/AA ratios of the entire cohort; LOW group with the levels ≤0.30 (n = 66) and HIGH group >0.30 (n = 66). The incidence of major adverse events (MAE), including major adverse limb events (MALE) and death from any cause, was determined. At a median follow-up interval of 24 months, MALE occurred in 40 patients (30.3%) and 11 patients (8.3%) died. Kaplan-Meier curve analysis demonstrated the survival probability from MAE was significantly worse in patients with EPA/AA ratio under the median (long-rank test χ(2) = 16.4; p < 0.001). Multivariate Cox regression analysis showed critical limb ischemia (hazard ratio [HR]: 3.44; 95% confidence interval [CI]: 1.84 to 6.46; p < 0.001) and the preprocedural serum EPA/AA ratios ≤0.30 (HR: 2.74; 95% CI: 1.33 to 5.65; p = 0.006) independently predicted MAE after EVT. CONCLUSIONS Lower serum EPA/AA ratios appear to be associated with a greater risk of MALE and death from any cause after EVT in patients with PAD caused by femoropopliteal artery lesions.

Lipoprotein(a) is an important factor to determine coronary artery plaque morphology in patients with acute myocardial infarction.

BackgroundLipoprotein(a) [Lp(a)] can influence the development and disruption of atherosclerotic plaques through its effect on lipid accumulation. The purpose of this study was to evaluate the relationship between serum Lp(a) levels and plaque morphology of an infarct-related lesion and non-infarct-related lesion of the coronary artery in acute myocardial infarction (AMI). Methods and resultsCoronary plaque morphology was evaluated in 68 patients (age 62.1±12.1 years, mean±SD; men n=58, women n=10) with AMI by intravascular ultrasound with radiofrequency data analysis before coronary intervention and by 64-slice computed tomography angiography within 2 weeks. Patients were divided into a group with an Lp(a) level of 25 mg/dl or more (n=20) and a group with an Lp(a) level of less than 25 mg/dl (n=48). Intravascular ultrasound with radiofrequency data analysis identified four types of plaque components at the infarct-related lesion: fibrous, fibrofatty, dense calcium, and necrotic core. The necrotic core component was significantly larger in the group with an Lp(a) level of 25 mg/dl or more than in the group with an Lp(a) level of less than 25 mg/dl (27.6±8.0 vs. 15.7±10.0%, P=0.0001). Coronary plaques were classified as calcified plaques, noncalcified plaques, mixed plaques, and low-attenuation plaques on 64-slice computed tomography angiography. Computed tomography indicated that the group with an Lp(a) level of 25 mg/dl or more had a greater number of total plaques, noncalcified plaques, and low-attenuation plaques in whole coronary arteries than did the group with an Lp(a) level of less than 25 mg/dl (5.3±1.8 vs. 3.7±2.2, P=0.0061; 4.0±2.0 vs. 1.2±1.3, P=0.0001; 2.2±2.1 vs. 0.5±0.7, P=0.0001, respectively). ConclusionElevated serum Lp(a) levels are associated with the number of plaques and plaque morphology. Patients with a high Lp(a) level during AMI require more intensive treatment for plaque stabilization.

Impact of statin use before the onset of acute myocardial infarction on coronary plaque morphology of the culprit lesion.

Statins favorably stabilize coronary plaque. We evaluated the impact of statin use before the onset of acute myocardial infarction (AMI) on culprit lesion plaque morphology. Patients (n = 127) with AMI were divided into either a statin group (n = 31) or a nonstatin group (n = 96) based on statin use before the onset of AMI. Coronary plaque morphology of the culprit lesion was evaluated using intravascular ultrasound virtual histology (IVUS-VH) with radiofrequency data analysis before coronary intervention. The IVUS-VH identified 4 types of plaque components: fibrous, fibrofatty, dense calcium, and necrotic core. The IVUS-VH showed less percentage of necrotic area, greater percentage fibrous area, and greater percentage of fibrofatty area of the culprit lesion in the statin group. In conclusion, statin use before the onset of AMI might have effects on coronary plaque morphology of the AMI culprit lesion with less necrotic core and greater fibrous and fibrofatty component.

Long-term outcome after catheter ablation of paroxysmal atrial fibrillation: Impact of different atrial fibrillation foci

BACKGROUND We aimed to determine whether differing foci in paroxysmal atrial fibrillation (PAF) affected the long-term outcome of catheter ablation (CA). METHODS A total of 865 consecutive PAF patients (age, 61±10years; 670 male) undergoing initial AF ablation were included. After pulmonary vein (PV) isolation, superior vena cava (SVC) isolation was performed for SVC foci; other non-PV foci were focally ablated. Long-term outcomes were compared among patients with SVC foci (Group SVC), other non-PV foci (Group Non-PV), and those without these foci (Group PV). RESULTS Groups PV, SVC, and Non-PV contained 740 (85.8%), 57 (6.6%), and 68 (7.6%) patients, respectively. Structural heart disease (P=0.01) and duration of AF history (P=0.04) were significantly associated with Group Non-PV, and female sex (P=0.0002) was significantly associated with Group SVC. AF recurrence-free rates at 5years in Group PV, SVC, and Non-PV were 62.0%, 66.3%, and 49.3%, respectively (P=0.03), after the initial CA, and 84.7%, 83.9%, and 77.0%, respectively (P=0.02), after the final CA. The duration of AF history (HR, 1.04, P<0.0001) and left atrial dimension (HR, 1.37 per 10mm increase, P=0.0003) were significant predictors of AF recurrence after the initial CA. Although Group Non-PV was weakly associated (HR 1.38, P=0.08) with AF recurrence, Group SVC was not associated with AF recurrence. CONCLUSIONS Long-term outcome of CA of PAF was significantly worse in patients with non-PV foci other than SVC foci. These foci may affect the outcome not independently but as an aspect of atrial remodeling.