Israel Medical Association Journal

Background: Syncope is a common clinical condition spanning from benign to life-threatening diseases. There is sparse information on the outcomes of syncopal patients who received an implantable cardiac defibrillator (ICD) for primary prevention of sudden cardiac death (SCD). 

Objectives: To assess the outcomes and prognosis of patients who underwent implantable cardiac defibrillator (ICD) implantation for primary prevention of SCD and compare them to patients who presented with or without prior syncope.

Methods: We compared the medical records of 75 patients who underwent ICD implantation for primary prevention of SCD and history of syncope to those of a similar group of 80 patients without prior syncope. We assessed the episodes of ventricular tachycardia (VT), ventricular fibrillation (VF), shock, anti-tachycardia pacing (ATP) and mortality in each group during follow-up.

Results: Mean follow-up was 893 days (810–976, 95%CI) (no difference between groups). There was no significant difference in gender or age. Patients with prior syncope had a higher ejection fraction rate (35.5 ± 12.6 vs. 31.4 ± 8.76, P = 0.02), experienced more episodes of VT (21.3% vs. 3.8%, P = 0.001) and VF (8% vs. 0%, P = 0.01), and received more electric shocks (18.7% vs. 3.8%, P = 0.004) and ATP (17.3% vs. 6.2%, P = 0.031). There were no differences in inappropriate shocks (6.7% vs. 5%, P = 0.74), cardiovascular mortality (cumulative 5 year estimate 29.9% vs. 32.2%, P = 0.97) and any death (cumulative 5 year estimate 38.1% vs. 48.9%, P = 0.18).

Conclusions: Patients presenting with syncope before ICD implantation seemed to have more episodes of VT/VF and shock or ATP. No differences in mortality were observed

 

Background: Chronic kidney disease (CKD) is often accompanied by impairment of cardiac function that may lead to major cardiac events. Erythropoietin (EPO), a kidney-produced protein, was shown to be beneficial to heart function. It was suggested that reduced EPO secretion in CKD may play a role in the initiation of heart damage. 

Objectives: To investigate molecular changes in the EPO/erythropoietin receptor (EPO-R) axis in rat cardiomyocytes using a rat model for CKD.

Methods: We established a rat model for CKD by kidney resection. Cardiac tissue sections were stained with Masson’s trichrome to assess interstitial fibrosis indicating cardiac damage. To evaluate changes in the EPO/EPO-R signaling cascade in the myocardium we measured cardiac EPO and EPO-R as well as the phosphorylation levels of STAT-5, a downstream element in this cascade.

Results: At 11 weeks after resection, animals presented severe renal failure reflected by reduced creatinine clearance, elevated blood urea nitrogen and presence of anemia. Histological analysis revealed enhanced fibrosis in cardiac sections of CKD animals compared to the sham controls. Parallel to these changes, we found that although cardiac EPO levels were similar in both groups, the expression of EPO-R and the activated form of its downstream protein STAT-5 were significantly lower in CKD animals.

Conclusions: CKD results in molecular changes in the EPO/EPO-R axis. These changes may play a role in early cardiac damage observed in the cardiorenal syndrome.

 

Background: Transvenous lead extraction can lead to tricuspid valve damage. 

Objectives: To assess the incidence, risk factors and clinical outcome of tricuspid regurgitation (TR) following lead extraction.

Methods: We prospectively collected data on patients who underwent lead extraction at the Sheba Medical Center prior to laser use (i.e., before 2012). Echocardiography results before and following the procedure were used to confirm TR worsening, defined as an echocardiographic increase of at least one TR grade. Various clinical and echocardiographic parameters were analyzed as risk factors for TR. Clinical and echocardiographic follow-up was conducted to assess the clinical significance outcome of extraction-induced TR.

Results: Of 152 patients who underwent lead extraction without laser before 2012, 86 (56%) (192 electrodes) had echocardiography results before and within one week following the procedure. New or worsening TR was discovered in 13 patients (15%). Use of mechanical tools and younger age at extraction were found on multivariate analysis to be factors for TR development (P = 0.04 and P = 0.03 respectively). Average follow-up was 22.25 ± 21.34 months (range 8–93). There were no significant differences in the incidence of right-sided heart failure (50% vs. 23%, P = 0.192) or hospitalizations due to heart failure exacerbations (37.5% vs. 11%, P = 0.110). No patient required tricuspid valve repair or replacement. Death rates were similar in the TR and non-TR groups (20% vs. 33%).

Conclusions: TR following lead extraction is not uncommon but does not seem to affect survival or outcomes such as need for valve surgery. Its long-term effects remain to be determined. 

 

Background: The kinetics of high sensitivity cardiac troponin T (hs-cTnT) levels after elective, biphasic, direct-current cardioversion for persistent atrial fibrillation/flutter remains unknown.

Methods: We examined hs-cTnT kinetics in 24 patients at baseline and at 2, 6 and 24 hours post-cardioversion, and again at 7 and 30 days. We also examined levels of creatine kinase, aspartate aminotransferase, lactate dehydrogenase, brain natriuretic peptide (BNP), and high sensitivity C-reactive protein (hs-CRP).

Results: Median (25th, 75th interquartiles) baseline hs-cTnT concentration was 19.8 (10.4, 35.2) ng/L with 14 patients presenting with levels above the 99th percentile (13 ng/L). Hs-cTnT levels did not change significantly over time although they tended to decrease by 30 days, 18.8 ng/L (12.5, 23.3). There was no significant rise in other markers of myocardial injury. Similarly, BNP and hs-CRP levels were elevated at baseline and tended to decrease over time.

Conclusions: Patients with persistent atrial fibrillation/flutter have elevated hs-cTnT levels, as part of a general rise in biomarkers such as BNP and hs-CRP, without a further rise after cardioversion. After cardioversion, there is a gradual non-significant decrease in biomarker levels over time, and thus a rise in hs-cTnT levels should not be attributed to cardioversion. 

 

Background: Left cardiac sympathetic denervation (LCSD) was reported to be effective in patients with intractable ryanodine receptor mutation-associated catecholaminergic polymorphic ventricular tachycardia (CPVT). 

Objectives: To report our experience with LCSD in calsequestrin (CASQ2) mutation-associated CPVT. 

Methods: LCSD was performed in three patients with CASQ2 mutation-associated CPVT with symptoms and exercise-induced ventricular arrhythmia despite high dose beta-blocker. 

Results: None of them experienced symptoms or exercise-induced ventricular arrhythmia after LCSD. However, all had recurrence of symptoms and/or exercise-induced ventricular arrhythmia after 6 months (6–18 months).

Conclusions: LCSD conferred short-term suppression but less than optimal long-term suppression of exercise-induced ventricular arrhythmia among CASQ2-associated CPVT patients.

 

Background: Cardiac resynchronization therapy (CRT) is a non-pharmacological option for patients with heart failure and interventricular dyssynchrony. Elevated red cell distribution width (RDW) reflects higher size and heterogeneity of erythrocytes and is associated with poor outcome in patients with chronic heart failure. 

Objectives: To examine the association between RDW levels and outcomes after CRT implantation.

Methods: We conducted a cohort analysis of 156 patients (126 men, median age 69.0 years) who underwent CRT implantation in our institution during 2004–2008. RDW was measured at three time points before and after implantation. Primary outcome was defined as all-cause mortality, and secondary outcome as hospital re-admissions. We investigated the association between RDW levels and primary outcome during a median follow-up of 61 months.

Results: Ninety-five patients (60.9%) died during follow-up. Higher baseline RDW levels were associated with all-cause mortality (unadjusted HR 1.35, 95%CI 1.20–1.52, P < 0.001). On multivariate analysis adjusted for clinical, electrocardiographic and laboratory variables, baseline RDW levels were associated with mortality (HR 1.33, 95%CI 1.16–1.53). RDW levels 6 months and 12 months post-implantation were also associated with mortality (HR 1.22, 95%CI 1.08–1.38, P = 0.001; and HR 1.15, 95%CI 1.01–1.32, P = 0.02, respectively). Patients who were re-admitted to hospital during follow-up (n=78) had higher baseline RDW levels as compared to those who were not (14.9%, IQR 14.0, 16.0% vs. 14.3%, IQR 13.7, 15.0%, respectively, P = 0.03). 

Conclusion: An elevated RDW level before and after CRT implantation is independently associated with all-cause mortality. 

 

Objectives: To assess the role of electrocardiography-gated CT-angiography (ECG-CTA) in the routine evaluation of CHD in neonates and infants particularly for the assessment of extracardiac findings.

Methods: The study cohort comprised 40 consecutive patients who underwent trans-thoracic echocardiography (TTE) and ECG-CTA. TTE and ECG-gated CTA findings regarding extracardiac vascular structures, coronary arteries and airways were compared with surgical or cardiac catheterization findings. Scans were evaluated for image quality using a subjective visual scale (from 1 to 4). Effective radiation dose was calculated for each scan.

Results: Median age was 28 ± 88 days and mean weight 3.7 ± 1.5 kg. Diagnostic quality was good or excellent (visual image score 3–4) in 39 of 40 scans (97.5%). ECG-CTA provided important additional information regarding extracardiac vascular structures and airway anatomy, complementing TTE in 75.6% of scans. Overall sensitivity of ECG-gated CTA for detecting extracardiac findings as compared with operative and cardiac catheterization findings was 97.6%. The calculated mean effective radiation dose was 1.4 ± 0.07 mSv (range 1.014–2.3 mSv).

Conclusions: ECG-CTA is an accurate modality for demonstrating extracardiac structures in complex CHD. It provides important complementary information to TTE regarding extracardiac vascular structures and coronary artery anatomy. This modality may obviate the need for invasive cardiac catheterization, thus exposing the patient to a much lower radiation dose.