Ofer Havakuk

Risk stratification in Brugada syndrome: Clinical characteristics, electrocardiographic parameters, and auxiliary testing

Risk stratification in Brugada syndrome remains a clinical challenge because the event rate is low but the presenting symptom is often cardiac arrest (CA). We review the data on risk stratification. A history of CA or malignant syncope is a strong predictor of spontaneous ventricular fibrillation (VF), whereas the prognostic value of a history of familial sudden death and the presence of a SCN5A mutation are less well defined. On the electrocardiogram, the presence of spontaneous type I electrocardiogram increases the risk for VF in all studies, whereas the presence of fragmented QRS complexes and early repolarization correlates with increased risk in several studies. Signal-averaged techniques using late potentials and microscopic T-wave alternans show some promising results in small studies that need to be confirmed. The value of electrophysiologic studies for predicting spontaneous VF remains controversial, and this includes programmed stimulation protocols that avoid a third extrastimuli or stimulation from the right ventricular outflow. Risk prediction is particularly challenging in children and women.

Comparison of early and late outcomes of TAVI alone compared to TAVI plus PCI in aortic stenosis patients with and without coronary artery disease

To assess the safety and effectiveness of performing percutaneous coronary intervention (PCI) before transcatheter aortic valve implantation (TAVI).

Everybody has Brugada syndrome until proven otherwise

Q7 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 Brugada syndrome is a genetic arrhythmogenic disorder manifesting itself in a peculiar electrocardiogram (ECG) and an increased risk of cardiac arrest from ventricular fibrillation (VF). The diagnostic ECG, demonstrating J-point elevation and 42-mm coved ST-segment elevation in the right precordial leads, is termed type I Brugada ECG. This diagnostic ECG, however, has such day-to-day variability that among high-risk patients undergoing numerous ECG recordings over time, only every third ECG is diagnostic while every third ECG is normal. Several maneuvers are therefore used to increase the diagnostic sensitivity of the ECG: (1) The use of “high electrodes” (placing the recording right-precordial ECG electrodes not only on the standard fourth intercostal space but also on the second and the third intercostal space) increases the odds of identifying a type I ECG by 30%–40%. (2) The use of 12-lead Holter recordings (particularly with high electrodes as described above) further increases the odds of recognizing the diagnostic ST-segment elevation at times when vagal tone is elevated, primarily at night but also after meals. (3) Recognition that sodium channel blockers temporarily worsen the conduction and repolarization abnormalities of Brugada syndrome led to the use of these drugs to unravel the diagnostic ECG. Miyazaki et al were the first to test the effects of sodium channel blockers on the ECG of Brugada syndrome (in 1996) by injecting disopyramide or procainamide into 3 patients with nondiagnostic ECG: all 3 developed type I Brugada ECG within seconds. Shortly thereafter, Brugada et al tested 34 cardiac arrest survivors with an intermittent Brugada ECG pattern and demonstrated a 100% sensitivity for unraveling the type I Brugada ECG in this patient subgroup. In the same study, there was a 100% concordance between a positive ajmaline test and the presence of a given sodium channel mutation in 13 relatives of probands with Brugada syndrome. The excellent sensitivity of these results paved the path for what would become widespread use of sodium channel blockers for diagnosing Brugada syndrome. Today, Brugada syndrome is diagnosed, under the right circumstances, “in patients with ST segment elevation with 105 106 107 108 Address reprint requests and correspondence: Dr Sami Viskin, Department of Cardiology, Tel Aviv Medical Center, Weizman 6, Tel Aviv 64239, Israel. E-mail address: samiviskin@gmail.com.

The Obesity Paradox in Patients Undergoing Transcatheter Aortic Valve Implantation

Obesity is a major risk factor for cardiovascular morbidity and mortality. A considerable number of studies, however, showed better outcomes for overweight patients undergoing cardiovascular interventions—the so called obesity paradox.

Prognostic significance of fever-induced Brugada syndrome

BACKGROUND In Brugada syndrome (BrS), spontaneous type 1 electrocardiogram (ECG) is an established risk marker for fatal arrhythmias whereas drug-induced type 1 ECG shows a relatively benign prognosis. No study has analyzed the prognosis of fever-induced type 1 ECG (F-type1) in a large BrS cohort. OBJECTIVES The objectives of this study were to assess the prognosis of F-type1 in asymptomatic BrS and to compare the effects of fever and drugs on ECG parameters. METHODS One hundred twelve patients with BrS who developed F-type1 were retrospectively enrolled. Prognosis was evaluated in 88 asymptomatic patients. In a subgroup (n = 52), ECG parameters of multiple ECGs (at baseline, during fever, and after drug challenge) were analyzed. RESULTS Eighty-eight asymptomatic patients had a mean age of 45.8 ± 18.7 years, and 71.6% (67 of 88) were men. Twenty-one percent (18 of 88) had a family history of sudden cardiac death, and 26.4% (14 of 53) carried a pathogenic SCN5A mutation. Drug challenge was positive in 29 of 36 patients tested (80.6%). The risk of ventricular fibrillation in asymptomatic patients was 0.9%/y (3 of 88; 43.6 ± 37.4 months). ST-segment elevation in lead V2 during fever and after drug challenge was not significantly different (0.41 ± 0.21 ms during fever and 0.40 ± 0.30 ms after drug challenge; P > .05). Fever shortened the PR interval compared to baseline, whereas drug challenge resulted in prolonged PR interval and QRS duration (PR interval: 169 ± 29 ms at baseline, 148 ± 45 ms during fever, and 202 ± 35 ms after drug challenge; QRS duration: 97 ± 18 ms at baseline, 92 ± 28 ms during fever, and 117 ± 21 ms after drug challenge). CONCLUSION Patients with BrS who develop F-type1 are at risk of arrhythmic events. F-type1 appears to develop through a more complex mechanism as compared with drug-induced type 1 ECG.

Comparison of Outcomes in Patients ≤85 Versus >85 Years of Age Undergoing Transcatheter Aortic-Valve Implantation

The impact of age on baseline characteristics and outcomes in patients with severe aortic stenosis who undergo transcatheter aortic valve implantation (TAVI) has not been thoroughly investigated. To describe the baseline clinical profile of TAVI patients aged >85 and ≤85 years and to evaluate the influence of age differences on outcomes, we evaluated a consecutive cohort of 293 patients who underwent transfemoral TAVI at the Tel Aviv Medical Center. The cohort was divided into 2 groups: patients aged >85 years (n = 93) and patients aged ≤85 years (n = 200). Mean age was 83 ± 5.3 years (range 63 to 98) for the entire cohort. Women comprised 70% of the older group and 57.5% of the younger age group (p = 0.043). Baseline clinical profile, including EuroSCORE index and preprocedural aortic valve area were similar in both age groups. Thirty-day mortality, major vascular complications, need for permanent pacemaker implantation, length of hospital stay, and improvement in functional class after the procedure showed no differences between the 2 groups. Adjustment for baseline clinical differences between groups did not change the results. In conclusion, among patients who underwent transfemoral TAVI, older patients (>85 years) experience similar benefits and outcomes regarding functional status, complication rates, and 30-day mortality.

Pregnancy and the Risk of Spontaneous Coronary Artery Dissection: An Analysis of 120 Contemporary Cases

Background— Because of the rarity of this condition, information on pregnancy-associated spontaneous coronary artery dissection is limited. We reviewed a large number of contemporary pregnancy-associated spontaneous coronary artery dissection cases in an attempt to define the clinical characteristics and provide management recommendations. Methods and Results— A literature search for cases of pregnancy-associated spontaneous coronary artery dissection reported between 2000 and 2015 included 120 cases; 75% presented with ST-segment–elevation myocardial infarction, and 80% had anterior myocardial infarction. Left anterior descending coronary artery was involved in 72% of cases, left main segment in 36%, and 40% had multivessel spontaneous coronary artery dissection. Ejection fraction was reduced to <40% in 44% of cases. Percutaneous coronary intervention was successful in only 50% of cases. Coronary artery bypass surgery was performed in 44 cases because of complex anatomy, hemodynamic instability, or failed percutaneous coronary intervention. Maternal complications included cardiogenic shock (24%), mechanical support (28%), urgent percutaneous coronary intervention (28%), urgent coronary artery bypass surgery (27.5%), maternal mortality (4%), and fetal mortality (2.5%). During follow-up for 305±111 days, there was a high incidence of symptoms because of persistent or new spontaneous coronary artery dissections, and 5 women needed heart transplantation or ventricular assist device implantation. Conclusions— Pregnancy-associated spontaneous coronary artery dissection is commonly associated with left anterior descending, left main, and multivessel involvement, which leads to a high incidence of reduced ejection fraction, and life-threatening maternal and fetal complications. Percutaneous coronary intervention is associated with low success rate and high likelihood of complications, and coronary artery bypass surgery is often required. Recurrent ischemic events because of persistent or new spontaneous coronary artery dissection are common during long-term follow-up.

Forced diuresis with matched hydration in reducing acute kidney injury during transcatheter aortic valve implantation (Reduce-AKI): study protocol for a randomized sham-controlled trial

BackgroundAcute kidney injury (AKI) is observed in up to 41% of patients undergoing transcatheter aortic valve implantation (TAVI) and is associated with increased risk for mortality. The aim of the present study is to evaluate whether furosemide-induced diuresis with matched isotonic intravenous hydration using the RenalGuard system reduces AKI in patients undergoing TAVI.Methods/DesignReduce-AKI is a randomized sham-controlled study designed to examine the effect of an automated matched hydration system in the prevention of AKI in patients undergoing TAVI. Patients will be randomized in a 1:1 fashion to the RenalGuard system (active group) versus non-matched saline infusion (sham-controlled group). Both arms receive standard overnight saline infusion and N-acetyl cysteine before the procedure.DiscussionThe Reduce-AKI trial will investigate whether the use of automated forced diuresis with matched saline infusion is an effective therapeutic tool to reduce the occurrence of AKI in patients undergoing TAVI.Trial registrationClinicaltrials.gov: NCT01866800, 30 April 30 2013.

Relation of Metabolic Syndrome With Long-Term Mortality in Acute and Stable Coronary Disease

Past studies examining the effects of the metabolic syndrome (MS) on prognosis in postangiography patients were limited in size or were controversial in results. The aim of the study was to examine the association of the MS and the risk for long-term mortality in a large cohort of patients undergoing coronary angiography for various clinical indications. Medical history, physical examination, and laboratory values were used to diagnose patients with the MS. Cox regression models were used to analyze the effect of MS on long-term all-cause mortality. We prospectively recruited 3,525 consecutive patients with a mean age of 66 ± 22 years (range 24 to 97) and 72% men. Thirty percent of the cohort had MS. Patients with MS were more likely to have advanced coronary artery disease and acute coronary syndrome (p <0.001). Patients with MS had more abnormalities in their metabolic and inflammatory biomarkers regardless of their clinical presentation. A total of 495 deaths occurred during a mean follow-up period of 1,614 ± 709 days (median 1,780, interquartile range 1,030 to 2,178). MS was associated with an increased risk of death in the general cohort (hazard ratio [HR] 1.27, 95% confidence interval [CI] 1.01 to 1.56, p = 0.02). MS had a significant effect on mortality in stable patients (HR 1.55, 95% CI 1.1 to 2.18, p = 0.01), whereas it did not have a significant effect on mortality in patients with acute coronary syndrome (HR 1.11, 95% CI 0.86 to 1.44, p = 0.42). In conclusion, MS is associated with increased mortality in postangiography patients. Its adverse outcome is mainly seen in patients with stable angina.

The Cardiovascular Effects of Cocaine

Cocaine is the leading cause for drug-abuse-related visits to emergency departments, most of which are due to cardiovascular complaints. Through its diverse pathophysiological mechanisms, cocaine exerts various adverse effects on the cardiovascular system, many times with grave results. Described here are the varied cardiovascular effects of cocaine, areas of controversy, and therapeutic options.