Background: The PRAETORIAN trial showed non-inferiority of the subcutaneous implantable cardioverter-defibrillator (S-ICD) compared to the transvenous ICD (TV-ICD) with regard to inappropriate shocks and complications. In contrast to the TV-ICD, the S-ICD cannot provide antitachycardia pacing (ATP) for monomorphic ventricular tachycardia (VT). This pre-specified secondary analysis evaluates appropriate therapy and whether ATP reduces the number of appropriate shocks. Methods: The PRAETORIAN trial was an international, investigator-initiated randomized trial, which included patients with an indication for ICD therapy. Patients with prior VTs below 170 bpm or refractory recurrent monomorphic VTs were excluded. In 39 centers, 849 patients were randomized to receive an S-ICD (N=426) or TV-ICD (N=423) and were followed for a median of 49.1 months. ICD programming was mandated by protocol. Appropriate ICD therapy was defined as therapy for ventricular arrhythmias. Arrhythmias were classified as discrete episodes and storm episodes (≥3 episodes within 24 hours). Analyses were performed in the modified intention-to-treat population. Results: In the S-ICD group, 86/426 patients received appropriate therapy, versus 78/423 patients in the TV-ICD group, during a median follow-up of 52 months (48-month Kaplan-Meier estimates 19.4% and 17.5%, P=0.45). In the S-ICD group, 83 patients received at least one shock, versus 57 patients in the TV-ICD group (48-month Kaplan-Meier estimates 19.2% and 11.5%, P=0.02). Patients in the S-ICD group had a total of 254 shocks, compared to 228 shocks in the TV-ICD group (P=0.68). First shock efficacy was 93.8% in the S-ICD group and 91.6% in the TV-ICD group (P=0.40). The first ATP attempt successfully terminated 46% of all monomorphic VTs, but accelerated the arrhythmia in 9.4%. Ten S-ICD patients experienced 13 electrical storms, versus 18 TV-ICD patients with 19 electrical storms. Patients with appropriate therapy had an almost two-fold increased relative risk of electrical storms in the TV-ICD group compared to the S-ICD group (P=0.05). Conclusions: In this trial, no difference was observed in shock efficacy of the S-ICD compared with the TV-ICD. Although patients in the S-ICD group were more likely to receive an ICD shock, the total number of appropriate shocks was not different between the two groups.

‘High-risk’ or ‘vulnerable’ plaques in the coronary arteries have characteristics that make them more prone to disruption and subsequent thrombosis – the mechanisms of most acute coronary syndromes (ACS). There are a number of imaging modalities that are capable of visualizing these features. This article discusses invasive modalities for identifying ‘high-risk’ plaque such as intravascular ultrasound, coronary angioscopy, optical coherence tomography, near-infrared spectroscopy and coronary thermography. It also discusses the use of noninvasive modalities such as computed tomography MRI and ultrasound. When these imaging modalities are combined with standard cardiac risk factors and more novel markers of systemic inflammation and thrombogenicity we can improve our ability to identify the ‘high-risk’ patient.

(1) Patients with vagal AF are younger, and invariably have paroxysmal lone AF. (2) SAPW is normal and significantly shorter in vagal AF when compared to patients with nonvagal AF. (3) This suggests that those in the vagal AF population have normal intraatrial conduction, which has implications for AF ablation in these patients.

Background: Current management guidelines for patients with Medtronic Sprint Fidelis ICD leads (Medtronic Inc., Minneapolis, MN, USA) include prominent use of Patient Alert TM , a feature in which the ICD generator emits audible beeps at two programmable frequencies. Because hearing loss is highly prevalent beyond the sixth decade of life, the utility of this feature is unclear. Therefore, we conducted a survey of patients' ability to hear the Medtronic Patient Alert TM . Methods: During visits to an outpatient device clinic, patients with Medtronic ICDs were evaluated for their ability to hear ICD tones. Results: The patient group consisted of 102 patients. Patients older than 70 years comprised 68% of the sample, with 16% between 60 and 70, and 17% younger than 60 years. Of the 102 patients, 59% (56% of males and 70% of females) were able to hear at least one tone. Ability to hear ICD tones decreased with advancing age. Among patients over 60 and 70 years, 52% and 43%, respectively (P < 0.001 vs. patients below 60 and 70 years), could hear at least one tone. Conclusions: The Patient Alert TM feature is not useful among a large proportion of ICD patients. Patients with Sprint Fidelis leads should be evaluated for their ability to hear audible ICD tones. For patients who cannot hear the Patient Alert TM feature, a wireless remote monitoring and/or daily application of a magnet by a caregiver should be considered. Device manufacturers should include nonauditory alert technologies such as wireless remote monitoring and vibratory stimulation in future devices. (PACE 2009; 32:1272-1275

Background The subcutaneous ICD (S-ICD) is developed to overcome lead-related complications and systemic infections, inherent to transvenous ICD (TV-ICD) therapy. The PRAETORIAN trial demonstrated that the S-ICD is non-inferior to the TV-ICD with regard to the combined primary endpoint of inappropriate shocks and complications. This prespecified secondary analysis evaluates all complications in the PRAETORIAN trial. Methods The PRAETORIAN trial is an international, multicenter, randomised trial in which 849 patients with an indication for ICD therapy were randomised to receive an SICD (N = 426) or TV-ICD (N = 423) and followed for a median of 49 months. Endpoints were device-related complications, lead-related complications, systemic infections and the need for invasive interventions. Results Thirty-six device-related complications occurred in 31 patients in the S-ICD group of which bleedings were the most frequent. In the TV-ICD group 49 complications occurred in 44 patients of which lead-dysfunction was most frequent (HR 0.69; P =0.11). In both groups half of all complications were within 30 days after implantation. Lead-related complications and systemic infections occurred significantly less in the S-ICD group compared to the TV-ICD group (P &lt;0.001, P =0.03 respectively). Significantly more complications required invasive interventions in the TV-ICD group compared to the S-ICD group (8.3% vs. 4.3%, HR 0.59; P =0.047). Conclusions This secondary analysis shows that, lead-related complications and systemic infections are more prevalent in the TV-ICD group compared to the S-ICD group. In addition, complications in the TV-ICD group were more severe as they required significantly more invasive interventions. This data contributes to shared decision making in clinical practice.