Dan Musat

Cardiac implantable electronic device infections: Incidence, risk factors, and the effect of the AigisRx antibacterial envelope

BACKGROUND Cardiac implantable electronic device (CIED) infection is associated with morbidity and mortality. OBJECTIVES To determine the incidence and risk factors for CIED infection, to develop a scoring index for risk stratification, and to analyze the effect of the AIGISRx envelope on infection rates. METHODS Consecutive patients who underwent a CIED procedure were identified and surveyed for 6 months for the development of an infection necessitating removal of all implanted hardware. RESULTS In the pre-envelope era, an infection occurred in 25 (1.5%) of 1651 patients. After its availability, an envelope was used in 275 (22%) of 1240 patients; an infection occurred in 8 (0.6%) patients in this era (P = .029 vs pre-envelope). In the overall cohort of 2891 patients, the infection rate was 1.2% and 3.5% in patients with an implantable cardioverter-defibrillator device and those with a cardiac resynchronization therapy defibrillator device, respectively (P = .018); in these patients, 7 independent risk factors predicted infection: early pocket re-exploration, male sex, diabetes, upgrade procedure, heart failure, hypertension, and glomerular filtration rate < 60 mL/min. A composite risk score (0-25; C index 0.72; 95% confidence interval 0.61-0.83) was created by weight, adjusting these 7 factors: 3 groups emerged-low risk (score 0-7; 1% infection), medium risk (score 8-14; 3.4% infection), and high risk (score ≥15; 11.1% infection). The envelope reduced infections by 79% and 100% in the medium- and high-risk groups, respectively. CONCLUSIONS CIED infection most commonly occurred in patients with an implantable cardioverter-defibrillator device and those with a cardiac resynchronization therapy defibrillator device. A composite score based on clinical variables appeared feasible for infection risk stratification. The AIGISRx envelope significantly lowered the risk of CIED infection. Randomized clinical data are warranted.

Treatment of Obstructive Hypertrophic Cardiomyopathy Symptoms and Gradient Resistant to First-Line Therapy With β-Blockade or Verapamil

Background—There is controversy about preferred methods to relieve obstruction in hypertrophic cardiomyopathy patients still symptomatic after &bgr;-blockade or verapamil. Methods and Results—Of 737 patients prospectively registered at our institution, 299 (41%) required further therapy for obstruction for limiting symptoms, rest gradient 61±45, provoked gradient 115±49 mm Hg, and followed up for 4.8 years. Disopyramide was added in 221 (74%) patients and pharmacological control of symptoms was achieved in 141 (64%) patients. Overall, 138 (46%) patients had surgical relief of obstruction (91% myectomy) and 6 (2%) alcohol septal ablation. At follow-up, resting gradients in the 299 patients had decreased from 61±44 to 10±25 mm Hg (P<0.0001); New York Heart Association class decreased from 2.7±0.7 to 1.8±0.5 (P<0.0001). Kaplan–Meier survival at 10 years in the 299 advanced-care patients was 88% and did not differ from nonobstructed patients (P=0.28). Only 1 patient had sudden death, a low annual rate of 0.06%/y. Kaplan–Meier survival at 10 years in the advanced-care patients did not differ from that expected in a matched cohort of the US population (P=0.90). Conclusions—Patients with obstruction and symptoms resistant to initial pharmacological therapy with &bgr;-blockade or verapamil may realize meaningful symptom relief and low mortality through stepped management, adding disopyramide in appropriately selected patients, and when needed, by surgical myectomy.

Long-term ECG monitoring using an implantable loop recorder for the detection of atrial fibrillation after cavotricuspid isthmus ablation in patients with atrial flutter

BACKGROUND In patients with atrial flutter who undergo cavotricuspid isthmus ablation, long-term electrocardiographic (ECG) monitoring may identify new onset of atrial fibrillation (AF). OBJECTIVES To ascertain, through the use of an implantable loop recorder (ILR) with a dedicated AF detection algorithm, the incidence, duration, and burden of new AF in these patients and to develop an optimal postablation ECG monitoring strategy. METHODS We enrolled 20 patients with flutter, a CHADS2 score of 2-3, and no prior episode of AF. After cavotricuspid isthmus ablation, we implanted an ILR, which was interrogated routinely; all stored ECGs were adjudicated. RESULTS During a mean follow-up of 382 ± 218 days, 3 patterns were observed. First, in 11 (55%) patients, stored ECGs confirmed AF at 62 ± 38 days after ablation. Second, in 4 (20%) patients, although the ILR suggested AF, episodes actually represented sinus rhythm with frequent premature atrial contractions and/or oversensing. Third, in 5 (25%) patients, no AF was observed. Episodes <4 hours were associated with low AF burden (<1%) or false detections. The 1-year freedom from any episode of AF >4 and >12 hours was 52% and 83%, respectively. CONCLUSIONS Our data show that many (but not all) patients develop new AF within the first 4 months of flutter ablation. Since external ECG monitoring for this duration is impractical, the ILR has an important role for long-term AF surveillance. Future research should be directed toward identifying the relationship between duration/burden of AF and stroke and improving existing ILR technology.

Malnutrition as Assessed by Nutritional Risk Index is Associated with Worse Outcome in Patients Admitted with Acute Decompensated Heart Failure: An ACAP-HF Data Analysis:

Malnutrition is common at hospital admission and tends to worsen during hospitalization. This controlled population study aimed to determine if serum albumin or moderate and severe nutritional depletion by Nutritional Risk Index (NRI) at hospital admission are associated with increased length of hospital stay (LOS) in patients admitted with acute decompensated heart failure (ADHF). Serum albumin levels and lymphocyte counts were retrospectively determined at hospital admission in 1740 consecutive patients admitted with primary and secondary diagnosis of ADHF. The Nutrition Risk Score (NRI) developed originally in AIDS and cancer populations was derived from the serum albumin concentration and the ratio of actual to usual weight, as follows: NRI = (1.519 × serum albumin, g/dL) + {41.7 × present weight (kg)/ideal body weight(kg)}. Patients were classified into four groups as no, mild, moderate or severe risk by NRI. Multiple logistic regressions were used to determine the association between nutritional risk category and LOS. Three hundred and eighty-one patients (34%) were at moderate or severe nutritional risk by NRI score. This cohort had lower BMI (24 ± 5.6 kg/m2), albumin (2.8±0.5 g/dL), mean NRI (73.5±9) and lower eGFR (50±33 mL/min per 1.73 m2). NRI for this cohort, adjusted for age, was associated with LOS of 10.1 days. Using the Multiple Logistic regression module, NRI was the strongest predictor for LOS (OR 1.7, 95% CI: 1.58–1.9; P=0.005), followed by TIMI Risk Score [TRS] (OR 1.33, 95% CI: 1.03–1.71; P=0.02) and the presence of coronary artery disease (OR 2.29, 95%CI: 1.03–5.1; P=0.04). Moderate and severe NRI score was associated with higher readmission and death rates as compared to the other two groups. Nutritional depletion as assessed by Nutritional Risk Index is associated with worse outcome in patients admitted with ADHF. Therefore; we recommend adding NRI to further risk stratify these patients.

Very long-term outcome after initially successful catheter ablation of atrial fibrillation

BACKGROUND The ablation of atrial fibrillation (AF) using pulmonary vein isolation is indicated when patients do not respond favorably to medical therapy. Successful procedures are accomplished in the majority of patients, but the outcome after many years of follow-up after ablation is unknown. OBJECTIVE To describe the long-term recurrence rate and pattern of AF after successful ablation. METHODS A prospectively identified cohort of 445 patients who demonstrated freedom from AF for at least 1 year postablation (single procedure in 391 [87.9%]) was followed for 66.0 ± 34.0 months. Patients were seen at least annually as outpatients and underwent regular electrocardiographic monitoring. RESULTS At 40.7 ± 27.0 months postablation, 97 (21.8%) patients experienced at least 1 episode of recurrent AF. The vast majority of events were symptomatic, and no serious clinical events were associated with AF recurrence (eg, stroke). There was a steady attrition rate reaching 16.3% and 29.8% at 5 and 10 years, respectively. In 29 patients (29.5%) of the patients, recurrences were self-limited; the remainder required either medical therapy or repeat ablation. By multivariate analysis, persistent AF (hazard ratio 3.08; P < .0001) and hypertension (hazard ratio 1.08; P = .009) were independent risk factors for the recurrence of AF. The presence of both factors placed the patient at high risk of recurrence: 37.6% at 5 years and 68.8% at 10 years. CONCLUSIONS Over the decade after a successful ablation of AF, most patients continue to demonstrate freedom from AF. At the highest risk of very late recurrence is the subset of patients with hypertension and prior persistent AF.

Prophylactic pulmonary vein isolation during isthmus ablation for atrial flutter: The PReVENT AF Study I

BACKGROUND Although catheter ablation of isthmus-dependent atrial flutter (AFL) is successful at eliminating the target arrhythmia, many patients subsequently experience new-onset atrial fibrillation (AF). OBJECTIVE The aim of this study was to determine whether AF can be prevented by prophylactic pulmonary vein ablation in patients with AFL. METHODS A prospective, single-blind, randomized clinical trial in patients whose sole arrhythmia was AFL without AF was conducted. Patients were randomized to cavotricuspid isthmus ablation alone or with concomitant pulmonary vein isolation. All patients received an implantable cardiac monitor. RESULTS Fifty patients completed the trial, and patients were well matched. Isthmus ablation was successful in all patients; pulmonary vein isolation was successful in 25 (100%) randomized patients. Procedure (P < .0001) and fluoroscopy (P < .0001) times were longer in the combined ablation group. More patients in the isthmus ablation-only group experienced new-onset AF during follow-up (52% vs. 12%; P = .003). The 1-year AF burden also favored the combined ablation group compared with the isthmus ablation-only group (8.3% vs. 4.0%; P = .034). In the isthmus ablation-only group, 8 (32%) patients subsequently underwent another ablation for AF. The performance of pulmonary vein isolation and male sex were independent predictors of freedom from AF. CONCLUSION In the PREVENT-AF Study I randomized clinical trial of patients in whom only typical AFL had been observed clinically, the addition of pulmonary vein isolation to cavotricuspid isthmus ablation resulted in a marked reduction of new-onset AF during clinical follow-up as assessed with a continuous implantable cardiac monitor.

Right Ventricular Dysfunction is a Strong Predictor of Developing Atrial Fibrillation in Acutely Decompensated Heart Failure Patients, ACAP-HF Data Analysis

BACKGROUND Heart failure and atrial fibrillation (AFib) are the twin epidemics of modern cardiovascular disease. The incidence of new-onset AFib in acute decompensated heart failure (ADHF) patients is difficult to predict and the short- and long-term outcomes of AFib in a cohort of patients admitted with ADHF are unknown. METHODS AND RESULTS A total of 904 patients admitted with ADHF were studied. Incidence of AFib on admission was recorded and a multivariate analysis was performed using echocardiographic parameters to specify the predictors of AFib incidence in this cohort. In 904 ADHF patients (57% male, mean age 69 ± 14 years), 81% had history of hypertension, 40% were diabetics, and 51% were smokers. A total of 63% of the patients had known heart failure (HF) with mean ejection fraction of 34% ± 21%, and 33% of the patients had ischemic cardiomyopathy as the etiology of HF. Echocardiographic parameters were: left atrial (LA) diameter 4.5 ± 0.8 cm, left ventricular end-systolic 4.1 ± 1.3 cm, left ventricular end-diastolic 5.3 ± 1.1 cm. Right ventricular dysfunction (RVD) was present in 34% of the patients. A total of 191 (21%) patients subsequently developed AFib with two thirds of the cases occurring in patients with RVD. Using a univariate analysis, older age (OR 1.02; P < .0001), history of HF (OR 2.93; P < .0001), LA dilation (OR 1.58; P < .0001), the presence of left ventricular hypertrophy (OR 3.01, P < .0001), and RVD (OR 4.93; P < .00001) were the strongest predictors for AFib. Controlling for LA size and left ventricular hypertrophy using a forward stepwise regression, RVD remained the strongest predictor (OR 4.45; P < .0001). Patients with RVD had more events (cardiac readmission and mortality) than those with normal RV (56% versus 38%; P < .00001), notably; all-cause mortality was 4.7%/year in the abnormal RV group versus 2.9%/year in the normal RV group; P < .05. RV function analyses by echocardiography further risk stratified these patients based on their rhythm categorizing those patients with abnormal RV and AFib as the ones with the worse prognosis. CONCLUSION RV dysfunction is a strong predictor for developing AFib in acutely decompensated systolic failure patients. Patients with AFib and RVD have the worse outcome specially when is combined with LV dysfunction, therefore; evaluation of RV function may substantiate the difference in HF prognosis.

Comparison of endovascular versus epicardial lead placement for resynchronization therapy.

Cardiac resynchronization therapy (CRT) has been shown to improve survival and symptoms in patients with severe left ventricular (LV) dysfunction, congestive heart failure, and prolonged QRS duration. LV lead placement is achieved by placing the lead in the coronary sinus, an endovascular approach, or by a minimally invasive robotic-assisted thoracoscopic epicardial approach. There are no data directly comparing the 2 methods. Patients eligible for CRT were randomized to the endovascular and epicardial arms. Coronary sinus lead placement was achieved using the standard technique, and epicardial leads were placed using a minimally invasive robotic-assisted thoracoscopic approach. The primary end point was a decrease in LV end-systolic volume index at 6 months. The secondary end points included 30-day mortality rate, measures of clinical improvement, 1-year electrical lead performance, and 1-year survival rate. The relative improvement of LV end-systolic volume index from baseline to 6 months was similar between the arms (28.8% for the transvenous [n = 12] vs 30.5% for the epicardial (n = 9) arm, p = 0.93). There were no significant differences in the secondary end points between the 2 groups. In conclusion, there were no differences in echocardiographic and clinical outcomes comparing a conventional endovascular approach versus robotic-assisted surgical epicardial LV lead placement for CRT in patients with heart failure. Surgical approaches are still a viable alternative when a transvenous procedure has failed or is not technically feasible.

Computational Method to Predict Esophageal Temperature Elevations During Pulmonary Vein Isolation

Background:  The esophagus is in close proximity to the posterior wall of the left atrium, which renders it susceptible to thermal injury during radiofrequency (RF) ablation procedures for atrial fibrillation (AF). Real‐time assessment of esophageal position and temperature (T °) during pulmonary vein (PV) isolation has not been extensively explored.

The Esophageal Temperature Probe: Helpful Monitoring Device or Inadvertent Amplifier of Risk?

Catheter ablation targeting the pulmonary veins or left atrial substrate, or both, has become an established strategy for the management of patients with drug refractory, symptomatic atrial fibrillation (AF). The number of AF ablation procedures has doubled in the past 4 years; in 2008, an estimated 80,000 AF ablation procedures were performed in the United States alone. Despite the increasing number of patients undergoing catheter ablation of AF, fundamental questions remain regarding procedural efficacy and safety. Atrioesophageal (AE) fistula is a rare but dreaded and devastating complication of catheter ablation for AF. Although the reported incidence is only about 0.03–0.2%, the resultant mortality is in excess of 75%.1-3 Since the initial reports of this complication, an intense effort has been undertaken to understand the pathophysiology underlying this condition and to develop means to prevent this complication. What is now apparent is that the A-E fistula is just the “tip of the iceberg.”4 Milder forms of esophageal injury that range from esophageal erythema to intramural hemorrhage to frank esophageal ulcers can occur in a significant number of patients undergoing catheter ablation of AF.5-8 With the addition of sophisticated imaging technologies such as radial endosonography, endoscopy can demonstrate morphological changes in the periesophageal connective tissue and the posterior wall of the left atrium (LA), even in the absence of gross changes in the esophageal mucosa.4 Importantly, animal models suggest that these esophageal lesions are a form of thermal injury in that there is a linear relationship between the measured esophageal temperature and the frequency with which esophageal (and periesophageal) injury occurs as well as the size of individual lesions.9,10 Over the past several years, investigators have reported on the merits of various intraprocedural interventions aimed at reducing the likelihood of inadvertent esophageal injury and thus an A-E fistula. These include some basic measures like reduction of energy when targeting the posterior LA wall or avoidance of lesions in this region and also techniques for real-time intraprocedural visualization of the esophagus,11,12 monitoring of ablation lesions using intracardiac echocar-