Chang Hee Kwon

Differential prognostic effect of intravascular ultrasound use according to implanted stent length.

It is unknown whether the use of intravascular ultrasound (IVUS) guidance during percutaneous coronary intervention can attenuate the stent length effect on clinical outcomes. The aim of the present study was to determine the differential prognostic effect of IVUS according to the implanted stent length. We enrolled 3,244 consecutive patients from the Interventional Cardiology Research In-cooperation Society-Drug-Eluting Stents (IRIS-DES) registry who had undergone single or overlapping stent implantation. The primary end point was major adverse cardiac events (MACE; a composite of death, myocardial infarction, and target vessel revascularization). The study population was divided by the tertiles of implanted stent length and IVUS usage. IVUS use was at the discretion of the operator. After adjusting for significant covariates, the stent length was significantly associated with the risk of MACE in the no-IVUS group (hazard ratio 1.13, 95% confidence interval 1.01 to 1.28, p = 0.042) but not in the IVUS group (hazard ratio 1.08, 95% confidence interval 0.97 to 1.20, p = 0.16). In addition, in patients with an implanted stent length of ≤22 mm (n = 998), the risk of MACE was not significantly different between the IVUS group and the no-IVUS group (hazard ratio 1.06, 95% confidence interval 0.50 to 2.28, p = 0.88). In contrast, in patients with a longer implanted stent length, the risk of MACE was significantly lower in the IVUS group than in the no-IVUS group (hazard ratio 0.47, 95% confidence interval 0.24 to 0.92, p = 0.027 for 23 to 32 mm, n = 1,109; hazard ratio 0.57, 95% confidence interval 0.33 to 0.98, p = 0.042 for ≥33 mm, n = 1,137). In conclusion, IVUS usage can attenuate the detrimental effect of the increase in the implanted stent length, supporting IVUS usage, particularly during percutaneous coronary intervention with long stent implantation.

Second coupling interval of nonsustained ventricular tachycardia to distinguish malignant from benign outflow tract ventricular tachycardias

BACKGROUNDnIdiopathic ventricular tachycardia (VT) originating from the outflow tract (OT) usually is considered a benign condition. In rare cases, patients with OT-VT suffer from syncope or even sudden cardiac death. OT-VT is frequently preceded by nonsustained VT (NSVT).nnnOBJECTIVEnThe purpose of this study was to clarify if the ECG parameters of NSVTs could differentiate malignant from benign OT-VT.nnnMETHODSnWe retrospectively evaluated patients without structural heart disease who had documented OT-NSVT on ECG. ECG parameters were compared between patients with syncope, aborted sudden cardiac death, or ventricular fibrillation (malignant group, n = 36) and patients without syncope (benign group, n = 40).nnnRESULTSnThere were no differences with regard to age and gender between the malignant and benign groups. On analysis of NSVT, the first coupling interval (CI) of NSVT was comparable between the 2 groups (458 ± 87 ms vs 485 ± 95 ms, P = .212). However, the second CI of NSVT beats was significantly shorter in the malignant group (313 ± 58 ms vs 385 ± 83 ms, P < .0001). During 48-month follow-up, the benign group had a significantly lower recurrence of clinical VT than the malignant group (P = .046). The malignant group frequently had more than 1 focus of VT, whereas the benign group showed only a single focus (1.82 vs 1.09, P = .023).nnnCONCLUSIONnThe second CI of NSVT in the malignant group was significantly shorter than that of the benign OT-VT group. Careful measurement of the second CI of NSVT may help identify the malignant form of OT-VT, enabling early treatment to prevent future cardiac events.

Comparison of dual versus triple antiplatelet therapy after drug-eluting stent according to stent length (from the pooled analysis of DECLARE trials).

There are no practical criteria for the use of triple antiplatelet therapy after drug-eluting stent (DES) implantation. In our present report, pooled analysis of 3 randomized studies in patients with diabetes mellitus (Drug-Eluting Stenting Followed by Cilostazol treatment reduces LAte Restenosis in patients with diabetes mellitus trial) and long coronary narrowings (Drug-Eluting Stenting Followed by Cilostazol Treatment Reduces Late Restenosis in Patients with Long Coronary Lesions trials I and II) compared triple (aspirin, clopidogrel, and cilostazol; triple group, nxa0= 700) and dual antiplatelet therapies (aspirin and clopidogrel; dual group, nxa0= 699) after DES implantation. Among pooled population (nxa0= 1,399 patients), 1,173 patients with follow-up angiography were divided into 3 stent length categories (≤20, 20 to 40, and >40xa0mm). There was no statistical significance of in-stent restenosis (ISR) in ≤20- and 20- to 40-mm categories between 2 groups. However, ISR rate was significantly reduced in triple versus dual group in >40-mm stent length category (12.4% vs 22.1%, pxa0= 0.008). In diabetic patients, triple group also showed significant reduction in the ISR rate in >40-mm stent length category (15.4% vs 32.3%, pxa0= 0.003). According to postprocedural minimal lumen diameter, triple group showed a trend toward a lower ISR than that of the dual group in all categories (pxa0= 0.033 for ≤2.5xa0mm, pxa0= 0.087 for 2.5 to 3.0xa0mm, and pxa0= 0.119 for >3.0xa0mm). In conclusion, the triple group had a significantly reduced ISR in patients with >40-mm stent length after DES implantation compared with the dual group. Therefore, this suggestion for use of triple antiplatelet therapy could be easily applied after DES implantation in routine clinical practice.

Transvenous Lead Extraction via the Inferior Approach Using a Gooseneck Snare versus Simple Manual Traction

Background and Objectives The number of patients with cardiac implantable electronic devices needing lead extraction is increasing for various reasons, including infections, vascular obstruction, and lead failure. We report our experience with transvenous extraction of pacemaker and defibrillator leads via the inferior approach of using a gooseneck snare as a first-line therapy and compare extraction using a gooseneck snare with extraction using simple manual traction. Subjects and Methods The study included 23 consecutive patients (43 leads) who underwent transvenous lead extraction using a gooseneck snare (group A) and 10 consecutive patients (17 leads) who underwent lead extraction using simple manual traction (group B). Patient characteristics, indications, and outcomes were analyzed and compared between the groups. Results The dwelling time of the leads was longer in group A (median, 121) than in group B (median, 56; p=0.000). No differences were noted in the overall procedural success rate (69.6% vs. 70%), clinical procedural success rate (82.6% vs. 90%), and lead clinical success rate (86% vs. 94.1%) between the groups. The procedural success rates according to lead type were 89.2% and 100% for pacing leads and 66.7% and 83.3% for defibrillator leads in groups A and B, respectively. Major complications were noted in 3 (mortality in 1) patients in group A and 2 patients in group B. Conclusion Transvenous extraction of pacemaker leads via an inferior approach using a gooseneck snare was both safe and effective. However, stand-alone transvenous extraction of defibrillator leads using the inferior approach was suboptimal.

Tachyarrhythmia Cycle Length in Appropriate versus Inappropriate Defibrillator Shocks in Brugada Syndrome, Early Repolarization Syndrome, or Idiopathic Ventricular Fibrillation

Background and Objectives Implantable cardioverter–defibrillators (ICDs) are indicated in patients with Brugada syndrome (BS), early repolarization syndrome (ERS), or idiopathic ventricular fibrillation (IVF) who are at high risk for sudden cardiac death. The optimal ICD programming for reducing inappropriate shocks in these patients remains to be determined. We investigated the difference in the mean cycle length of tachyarrhythmias that activated either appropriate or inappropriate ICD shocks in these three patient groups to determine the optimal ventricular fibrillation (VF) zone for minimizing inappropriate ICD shocks. Subjects and Methods We selected 41 patients (35 men) (mean age±standard deviation=42.6±13.0 year) who received ICD shocks between April 1996 and April 2014 to treat BS (n=24), ERS (n=9), or IVF (n=8). Clinical and ICD interrogation data were retrospectively collected and analyzed for all events with ICD shocks. Results Of the 244 episodes, 180 (73.8%) shocks were appropriate and 64 (26.2%) were inappropriate. The mean cycle lengths of the tachyarrhythmias that activated appropriate and inappropriate shocks were 178.9±28.7 ms and 284.8±24.4 ms, respectively (p<0.001). The cutoff value with the highest sensitivity and specificity for discriminating between appropriate and inappropriate shocks was 235 ms (sensitivity, 98.4%; specificity, 95.6%). When we programmed a single VF zone of ≤270 ms, inappropriate ICD shocks were reduced by 70.5% and appropriate shocks were missed in 1.7% of these patients. Conclusion Programming of a single VF zone of ≤270 ms in patients with BS, ERS, or IVF could reduce inappropriate ICD shocks, with a low risk of missing appropriate shocks.

Role of Coronary Artery Calcium Scoring in Detection of Coronary Artery Disease according to Framingham Risk Score in Populations with Low to Intermediate Risks

Current guidelines recommend that coronary artery calcium (CAC) screening should only be used for intermediate risk groups (Framingham risk score [FRS] of 10%–20%). The CAC distributions and coronary artery disease (CAD) prevalence in various FRS strata were determined. The benefit to lower risk populations of CAC score-based screening was also assessed. In total, 1,854 participants (aged 40–79 years) without history of CAD, stroke, or diabetes were enrolled. CAC scores of > 0, ≥ 100, and ≥ 300 were present in 33.8%, 8.2%, and 2.9% of the participants, respectively. The CAC scores rose significantly as the FRS grew more severe (P < 0.01). The total CAD prevalence was 6.1%. The occult CAD prevalence in the FRS ≤ 5%, 6%–10%, 11%–20%, and > 20% strata were 3.4%, 6.7%, 9.0%, and 11.6% (P < 0.001). In multivariate logistic regression analysis adjusting, not only the intermediate and high risk groups but also the low risk (FRS 6%–10%) group had significantly increased odds ratio for occult CAD compared to the very low-risk (FRS ≤ 5%) group (1.89 [95% confidence interval, CI, 1.09–3.29] in FRS 6%–10%; 2.48 [95% CI, 1.47–4.20] in FRS 11%–20%; and 3.10 [95% CI, 1.75–5.47] in FRS > 20%; P < 0.05). In conclusion, the yield of screening for significant CAC and occult CAD is low in the very low risk population but it rises in low and intermediate risk populations.

Real-world comparison of non-vitamin K antagonist oral anticoagulants and warfarin in Asian octogenarian patients with atrial fibrillation.

Background The efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin in Asian octogenarian atrial fibrillation (AF) patients have not been established in a real-world setting. We aimed to evaluate the efficacy and safety of NOACs and warfarin in Korean octogenarian patients. Methods A total of 293 consecutive patients aged ≥ 80 years with non-valvular AF who had taken either NOACs (148 cases, 50.5%) or warfarin (145 cases, 49.5%) were retrospectively reviewed. The efficacy outcome was the composite of stroke or systemic embolism. The safety outcome was major bleeding. Results The follow-up duration was 375 patient-years (172 patient-years with NOACs and 203 patient-years with warfarin). Patients on NOACs were slightly older (P = 0.006) and had slightly higher HAS-BLED scores (P = 0.034). The efficacy of both anticoagulants was high (1.16% for NOACs vs. 2.98% for warfarin per 100 patient-years, P = 0.46). The safety outcome was relatively high in both NOACs and warfarin groups (8.96% vs. 12.46%, P = 0.29). The efficacy and safety outcomes tended to decrease non-significantly in low dose NOACs than in common dose NOACs or warfarin (0.85% vs. 1.84% vs. 2.98% in efficacy outcome, P = 0.69; and 6.97% vs. 13.29% vs. 12.46% in safety outcome, P = 0.34). Conclusions NOACs were highly effective for prevention of stroke or systemic embolism in Asian octogenarian AF patients. However, major bleeding occurred excessively high in both anticoagulant groups. Further study is required on the optimal anticoagulant regimen in octogenarian population.