Jinqi Fan

Radiofrequency Ablation Versus Antiarrhythmic Medication for Treatment of Ventricular Premature Beats From the Right Ventricular Outflow Tract Prospective Randomized Study

Background—The purpose of this study was to compare the efficacy of radiofrequency catheter ablation (RFCA) versus antiarrhythmic drugs (AADs) for treatment of patients with frequent ventricular premature beats (VPBs) originating from the right ventricular outflow tract (RVOT). Methods and Results—A total of 330 eligible patients were included in the study and were randomly assigned to RFCA or AADs group. The absolute number and the burden of VPBs on 12-lead Holter monitors were measured at baseline and at 1st, 3rd, 6th, and 12th months after randomization. Left ventricular eject fraction was evaluated by transthoracic echocardiogram at baseline and at 3 and 6 months after randomization. During the 1-year follow-up period, VPB recurrence was significantly lower in patients randomized to RFCA group (32 patients, 19.4%) versus AADs group (146 patients, 88.6%; P<0.001, log-rank test). In a Poisson generalized estimating equations (GEE) regression model, RFCA was associated with a greater decrease in the burden of VPBs (incidence rate ratio 0.105; 95% confidence intervals [0.104–0.105]; P<0.001) compared with AADs. In a liner GEE model, the left ventricular eject fraction had a tendency to increase after the treatment in both groups (coefficient, 0.584; 95% confidence intervals [0.467–0.702]; P<0.001). In a Cox proportional model, the QS morphology in lead I was the only predictor of VPB recurrence free for catheter ablation (hazards ratio, 0.154; 95% confidence intervals [0.044–0.543]; P=0.004). Conclusions—Catheter ablation is more efficacious than AADs for preventing VPB recurrence in patients with frequent VPBs originating from the RVOT. QS morphology in lead I was associated with better outcome after ablation.

Predictors of late recurrence of atrial fibrillation after catheter ablation

BACKGROUND To predict the recurrence of atrial fibrillation is important for selecting patients who will be undergoing catheter ablation, several studies respectively evaluated the risk factor of the recurrence of atrial fibrillation post-ablation. OBJECTIVE To investigate the factors predicting the recurrence of atrial fibrillation (AF) after catheter ablation. METHODS 186 patients (55.12 ± 12.06 years, 123 male) including 161 paroxysmal AF and 25 non-paroxysmal AF who underwent catheter ablation were studied. Clinical datum before and during ablation were recorded, and systematic follow-up was conducted after ablation. Univariate and multivariate analyses were carried out to determine the factors predicting late recurrence of AF (LRAF) which means AF recurrence after 3 months. RESULTS There were 47(25.27%) patients who experienced LRAF. Multivariate Logistic regression analysis was carried out to the parameters that P<0.10 in the univariate analysis, which includes overweight/obesity, metabolic syndrome (MetS), AF categories, duration of AF history, left atrial diameter (LAD), diabetes mellitus, ablation strategies, procedural failure and early recurrence of AF after ablation (ERAF). Ultimately, the results demonstrated that overweight/obesity (OR=4.71, 95% CI 1.71-12.98, P=0.003), MetS (OR=4.41, 95% CI 1.56-12.46, P=0.005), procedural failure (OR=58.34, 95% CI 6.83-498.34, P<0.001), and ERAF (OR=3.18, 95% CI 1.07-9.44, P=0.037) were independent predictors of AF recurrence after ablation. CONCLUSION Overweight/obesity, metabolic syndrome, procedural failure and ERAF are independent predictors of late recurrence of atrial fibrillation in this group of patients.

The Role of Continuous Positive Airway Pressure in Blood Pressure Control for Patients With Obstructive Sleep Apnea and Hypertension: A Meta‐Analysis of Randomized Controlled Trials

The aim of this study was to review the effect of continuous positive airway pressure (CPAP) on blood pressure (BP) in patients with obstructive sleep apnea (OSA) and hypertension. Biomedical databases were searched for randomized controlled trials (RCTs) comparing CPAP with control among these patients. Seven RCTs reporting 24‐hour ambulatory BP were identified for meta‐analysis. CPAP was associated with significant reductions in 24‐hour ambulatory systolic blood pressure (SBP) (−2.32 mm Hg; 95% confidence interval [CI], −3.65 to −1.00) and diastolic blood pressure (DBP) (−1.98 mm Hg; 95% CI, −2.82 to −1.14). CPAP led to more significant improvement in nocturnal SBP than that in diurnal SBP. Subgroup analysis showed that patients with resistant hypertension or receiving antihypertensive drugs benefited most from CPAP. Meta‐regression indicated that CPAP compliance, age, and baseline SBP were positively correlated with decrease in 24‐hour DBP, but not reduction in 24‐hour SBP.

Effect of Nifedipine Versus Telmisartan on Prevention of Atrial Fibrillation Recurrence in Hypertensive Patients

It is controversial whether angiotensin II receptor blockers provide better protection than calcium antagonists against atrial fibrillation (AF) recurrence in hypertensive patients. This study was designed to compare the effect of nifedipine- and telmisartan-based antihypertensive treatments for preventing AF recurrence in hypertensive patients with paroxysmal AF. A total of 149 hypertensive patients with paroxysmal AF were randomized to nifedipine- or telmisartan-based antihypertensive treatment groups. The target blood pressure (BP) was <130/80 mm Hg. Clinic BP, ECG, Holter monitoring, and echocardiography were followed up for 2 years. The primary end point was the incidence of overall and persistent AF recurrence. During follow-up, there was no statistical difference in the rate of patients lowering to target BP between both groups, whereas nifedipine group had slightly better BP control but similar heart rate control at 24 months. The incidence of AF recurrence was similar in both groups (nifedipine versus telmisartan: 58.7% versus 55.4%; P=0.742), and Kaplan–Meier analysis showed no significant difference in the freedom from AF recurrence (log-rank test; P=0.48). However, the rate of developing persistent AF in telmisartan group was lower than that in nifedipine group (5.4% versus 16.0%; P=0.035). Patients in telmisartan group had lower values of left atrial diameter, left atrial volume index, and left ventricular mass index at the end of follow-up. The effects of telmisartan in preventing AF recurrences in hypertensive patients with paroxysmal AF after intensive lowering BP is similar to that of nifedipine, but telmisartan has more potent effects on preventing progression to persistent AF.

Effects of renal sympathetic denervation using saline-irrigated radiofrequency ablation catheter on the activity of the renin-angiotensin system and endothelin-1.

Introduction: Excessive activation of the sympathetic nervous system (SNS) and the renin-angiotensin system (RAS) are crucial and interacted closely in the pathogenesis of chronic cardiovascular diseases. This study investigated the effects of renal denervation (RDN) on the RAS. Materials and methods: Eight Chinese Kunming dogs underwent bilateral RDN utilizing saline-irrigated radiofrequency ablation catheter. Blood pressure (BP) measurements, blood sampling assays and renal angiography were performed at baseline, 30 min, one month and three months after ablation. Results: During three months of follow-up, RDN caused a significant and uniform reduction in plasma level of renin, angiotensin II, and endothelin-1(ET-1), with the reduction of –5.7±6.8 (p=0.049), –19.4±19.3 (p=0.025), and –22.4±21 pg/ml (p=0.02) for plasma renin, –10.6±7.2 (p=0.004), –15.9±8.8 (p=0.001), and –15.2±9.6 pg/ml (p=0.003) for plasma angiotensin II, as well as –3.9±3 (p=0.007), –10.8±5 (p<0.001), and –14.6±6.1 pg/ml (p<0.001) for plasma ET-1. RDN utilizing a saline-irrigated catheter also caused a progressive and substantial BP reduction of –19±22/–8±13, –30±13/–13±14, and –36±20/–16±14 mm Hg (p=0.045, p<0.001, and p<0.002 for systolic BP; p=0.14, p=0.036, and p=0.014 for diastolic BP) without ablation-related complications. Conclusion: RDN substantially decreased BP and also significantly decreased the plasma levels of RAS and ET-1, which might be implicated in the mechanism of BP reduction by RDN.

Angiotensin-(1-7) attenuates angiotensin II-induced signalling associated with activation of a tyrosine phosphatase in Sprague-Dawley rats cardiac fibroblasts.

Angiotensin‐(1–7) [ANG‐(1–7)] mediates vasodilation, antiproliferation, anti‐apoptosis and antifibrosis, therefore, it opposes the effects of angiotensin II (ANG II). However, the detailed signal transduction mechanism following the Mas receptor activated by ANG‐(1–7) is still poorly understood. Src homology2‐containing inositol phosphatase 1 (SHP‐1), a redoxsensitive protein tyrosine phosphatase, negatively influences downstream signalling molecules, such as mitogen‐activated protein kinases (MAPKs), through dephosphorylation, thereby inhibiting proliferative and profibrotic signalling induced by ANG II. Therefore, we hypothesised that SHP‐1 may mediate the antiproliferative signalling of ANG‐(1–7) through the regulation of the dynamic balance of MAPKs and SHP‐1 in isolated cardiac fibroblasts. Primary culture of neonatal Sprague–Dawley rats cardiac fibroblasts was treated separately with different interventions to investigate this issue.

Efficacy and safety of zotarolimus-eluting stents compared with sirolimus-eluting stents in patients undergoing percutaneous coronary interventions — A meta-analysis of randomized controlled trials

BACKGROUND Whether ZES can further improve angiographic and clinical outcomes compared to SES still remains uncertain. OBJECTIVES The aim of this study was to assess the efficacy and safety of zotarolimus-eluting stents (ZES) compared with sirolimus-eluting stents (SES) in patients undergoing percutaneous coronary interventions (PCI). METHODS Major electronic information sources were explored for randomized controlled trials comparing ZES with SES among patients undergoing PCI during at least 9 months follow-up. The primary efficacy outcomes were target lesion revascularization (TLR), target vessel revascularization (TVR), and major adverse cardiac events (MACE); safety outcomes were stent thrombosis (ST), myocardial infarction (MI), and cardiac death. RESULTS Seven comparative studies were identified (a total of 5983 patients). When compared with ZES at 12-month follow-up, SES significantly reduced risk of MACE (relative risk [RR]: 0.74, 95% confidence interval [CI]: 0.61 to 0.89, p=0.002), and TLR (RR:0.39; 95% CI: 0.29 to 0.52; p<0.00001), without significant differences in terms of TVR (RR:0.68, 95% CI: 0.38 to 1.20; p=0.18), ST (RR:0.71; 95% CI: 0.39 to 1.31; p=0.28), cardiac death (RR:0.83; 95% CI: 0.49-1.42, p=0.50) or MI (RR:1.08; 95%CI: 0.80 to 1.45; p=0.62). CONCLUSIONS At 12-month follow-up, SES are superior to ZES in reducing the incidences of TLR and MACE in patients undergoing PCI, without significant differences in terms of TVR, ST, cardiac death, and MI.

Blockade of angiotensin II improves hyperthyroid induced abnormal atrial electrophysiological properties.

BACKGROUND Previous studies reported that RAS inhibitors prevented atrial fibrillation by improving atrial electrical and structural remodeling. However, the effect of RAS inhibitors on the substrates of atrial fibrillation (AF) underlying hyperthyroid is unclear. METHODS Forty rabbits were assigned to four groups: sham group, thyroxine group, benazepril group and irbesartan group (10 per group). The atrial effective refractory period (AERP) was measured. The physiologic rate adaptation and the AF vulnerability were evaluated. The real-time PCR, Western blot or fluorescent immunohistochemistry was performed to detect the expression of AF related Ca+, K+ channel and gap junction. RESULTS No significant difference was found in AERP among the thyroxine group, benazepril group and irbesartan group (75.13±5.41ms vs. 76.63±4.44ms, 79±4.95ms, P=0.28). However, benazepril or irbesartan could reduce AF vulnerability underlying hyperthyroid (75% vs. 37%, 44%, for thyroxine group, benazepril group and irbesartan group, respectively), and significantly improved physiologic rate adaptation of the AERP. Furthermore, both drugs significantly reduced L-Ca(2+) channel related subunits (α1C or α1D) and interstitial fibrosis (17.1±2.2% vs. 12.3±1.8, 11.7±1.2%, P<0.01, for thyroxine group, benazepril group and irbesartan group, respectively), increased lateral/polar connection of Cx43 (1.04±0.16 vs. 1.33±0.29,1.28±0.25, P<0.01, for thyroxine group, benazepril group and irbesartan group, respectively) and improved the abnormal distribution of gap junctions (Cx40, Cx43) underlying hyperthyroid. CONCLUSION Blockade of angiotensin II could improve abnormal atrial electrophysiological properties and further reduce AF vulnerability by extenuating ion channel, gap junction and structural remodeling in experimental thyrotoxic rabbits.

Rate vs. rhythm control in patients with atrial fibrillation — An updated meta-analysis of 10 randomized controlled trials

Atrial fibrillation (AF) is the most common cardiac arrhythmia, affectingmore than 2 million adults in theUnited States [1]. Rate control and rhythm control, both combined with anticoagulation therapy, are two fundamental strategies to treat AF. A series of randomized controlled trials (RCTs) were performed to compare the two strategies, but which one is better still has been the focus of controversy [2–11]. Therefore, we systematically performed an updated meta-analysis to compare rate and rhythmcontrol strategy in terms of all causemortality and worsening heart failure. We included studies if they met: 1) a study population with nonvalvular AF, 2) comparison of a ventricular rate control strategy and rhythm control strategy, 3) prospective randomized controlled trial, 4) intention-to-treat principle, 5) follow-up period N1 year. Electronic and literature search was performed in MEDLINE, The Cochrane Library, The Clinical Trials and Embase Database or the abstract of ACC (American College of Cardiology), AHA (AmericanHeart Association), and ESC (European Society of Cardiology) up to June 30, 2011 using the search term “atrial fibrillation, rate control, rhythm control, randomized trial”. Fig. 1 shows the study selection process. Finally, ten RCTs [2–11] were included in this meta-analysis. The baseline characteristics of included studies were presented in Table 1. The therapeutic approaches included atrioventricular node blockade: beta-blockers, digitalis or calcium blockers in the rate control group and antiarrhythmic agents, electrical cardioversion in the rhythm control group. The anticoagulation therapy was implemented according to the guideline. Amiodarone combined electrical cardioversion was the frequently used regimen in rhythm control group. Data for all cause mortality was reported in all included trials [2– 11]. There was no significant result in individual study regarding this outcome.When results from10 trialswere pooled, the impact of rate and rhythm control strategies still appeared to be equivalent on all cause mortality (5.3% vs. 5.0% per year; OR: 1.03; 95% CI: 0.84–1.26) with no significant heterogeneity (P=0.44, Ib25%). When we excluded 5 studies [2, 4, 5, 8, 9]withmeanageN65, rate control groupwas associated with a significant higher risk of all cause mortality when compared with rhythm control group (3.6% vs.1.9% per year; OR: 1.89; 95% CI: 1.01–3.53) with no significant heterogeneity (P=0.32, Ib25%) (Fig. 2). Data for worsening heart failure was reported in 6 studies [2–4, 7, 9, 10], thepooled result showed that the rate and rhythmcontrol grouphad a similar rate of worsening heart failure (3.81% vs. 3.61% per year; OR: 1.04; 95% CI: 0.80–1.36) with no significant heterogeneity (P=0.20; Ib50%). when we excluded studies with mean age N65 [2, 4, 9], the pooled result showed that rate control grouphad a significanthigher risk ofworsening heart failure events (2.3% vs. 0.3% per year; OR: 5.6; 95%CI: 1.44–21.69)with no significant heterogeneity (P=0.85, Ib25%) (Fig. 3). There was no significant difference on thromboembolic events (1.49% vs. 1.46% per year; OR: 1.02; 95% CI: 0.71–1.48) and bleeding events (1.78% vs. 1.73% per year; OR: 1.02; 95% CI: 0.70–1.49) between rate and rhythm control, even in the mean age b65 subgroup, (2.67% vs. 1.80% per year; OR: 1.49; 95% CI: 0.76 to 2.90) for thromboembolic events, (0.84% vs. 0.97% per year; OR: 0.86; 95% CI: 0.31–2.41) for bleeding events, respectively. Strategy to manage AF is expected by years not days. A survival analysis for the AFFIRM study showed that the maintenance of sinus was associated with a 47% reduction of overall mortality, whereas, the use of anti-arrhythmic drugs increased the risk of death by 49%. The survival benefit of rhythm control was greatly negated by the side effect of anti-arrhythmic drugs but not rate control strategy [12]. Age was correlative predictive factor inversely related to cardiac function and success rate of restoration of sinus rhythm. Younger AF patients were observed to have shorter AF duration, smaller atrial volume and higher success rate of reestablishment of sinus rhythm, which suggested these patients receiving rhythm control strategy tend to have higher success rate and more survival benefit. Heart failure usually complicated AF, and it helps increase the cardiovascular mortality. Annual incidence of worsening heart failure was 3.7% in this meta-analysis, with the highest rate (12.7%) occurred in study conducted by Roy et al.s study [9], where death from heart failure occupied 30% of total mortality. The meta-analysis revealed that rhythm control strategy in younger AF patients was associated with a significantly lower risk of worsening heart failure compared with rate control strategy. It is worth mentioning that this positive result from rhythm control strategy was mostly based on pharmacological therapy and electrical cardioversion but not ablation yet. In summary, this meta-analysis suggests that rhythm control strategy may be preferable to younger AF patient for all cause mortality and worsening heart failure.

Comparison of Saline-Irrigated Catheter vs. Temperature-Controlled Catheter for Renal Denervation in a Canine Model

BACKGROUND The effectiveness of catheter-based renal denervation (RDN) remains controversial. Although the reasons for this have not yet been elucidated, ineffective denervation appears to be an important factor. The present study aimed to investigate the difference in RDN between a saline-irrigated catheter (SIC) and a temperature-controlled catheter (TCC). METHODS Dogs (n = 6) from the Kunming province in Chinese were ablated; the SIC was introduced into the right renal artery, while the TCC was introduced into the left renal artery. After 6 months, histopathology and renal angiography were performed, and the change in neural density was evaluated using morphometric software. The average values of heart rate (HR), blood pressure (BP), and catecholamine metabolites were assessed at baseline and follow-up. RESULTS Histopathology showed nerve demyelination and denaturation, as well as interstitial hyperplasia, although these changes were more pronounced when the SIC was used. The change in neural density was greater and ablation was deeper when the SIC was used. Intimal hyperplasia was greater when the TCC was used, whereas medial hyperplasia was greater when the SIC was used. A trend toward a decrease in HR, BP, metanephrine, and normetanephrine between baseline and follow-up was observed. CONCLUSIONS Our findings suggest that SIC ablation results in more extensive neural degeneration, deeper penetration, and less extensive intimal hyperplasia than TCC ablation for RDN.