Safety and feasibility of intravenous sotalol loading for the prevention of ventricular arrhythmias

BACKGROUND

The use of intravenous (IV) sotalol loading following recent U.S. Food and Drug Administration (FDA) approval of a 1-day loading protocol has reduced the obligatory 3-day hospital stay for sotalol initiation when given orally. Several studies have recently demonstrated the safety and feasibility of IV loading for patients with atrial arrhythmias. However, there is a paucity of data on the feasibility and safety of IV sotalol loading for patients with ventricular arrhythmias. This study aims to assess the safety, feasibility, and length of stay (LOS) outcomes of IV sotalol loading for the prevention of ventricular arrhythmias.

METHODS

A retrospective analysis was performed of all patients undergoing IV sotalol loading and oral sotalol initiation for ventricular arrhythmias, or IV sotalol loading for atrial arrhythmias between August 2021 and December 2023 at Northwestern University. Baseline characteristics, success of sotalol initiation/loading, changes in heart rate (HR) and QT/QTc, safety, and LOS were compared between patients undergoing sotalol loading/initiation for ventricular arrhythmias (IV vs. PO) and between patients undergoing IV sotalol loading for ventricular arrhythmias vs. for atrial arrhythmias.

RESULTS

A total of 28 patients underwent sotalol loading/initiation for ventricular arrhythmias (N = 15 IV and N = 13 PO) and 41 patients underwent IV sotalol loading for atrial arrhythmias. Baseline characteristics of congestive heart failure history and left ventricular ejection fraction were worse in the ventricular arrhythmias group. There was no significant difference in the successful completion of IV sotalol loading for ventricular arrhythmias compared to oral sotalol initiation for ventricular arrhythmias or IV sotalol loading for atrial arrhythmias (86.7% vs. 92.3% vs. 90.2%, p = 0.88). There was a significant increase in ΔQTc following IV sotalol infusion for ventricular arrhythmias compared to following PO sotalol initiation for ventricular arrhythmias (46.4 ± 29.2 ms vs. 8.9 ± 32.6 ms, p = 0.004) and following IV sotalol infusion for atrial arrhythmias (46.4 ± 29.2 ms vs. 24.0 ± 25.1 ms, p = 0.018). ΔHR following IV sotalol infusion for ventricular arrhythmias was similar to ΔHR following PO sotalol initiation for ventricular arrhythmias and ΔHR following IV sotalol infusion for atrial arrhythmias (- 7.5 ± 8.7 bpm vs. - 8.5 ± 13.9 bpm vs. - 8.3 ± 13.2 bpm, p = 0.87). There were no significant differences in discontinuation for QTc prolongation (6.7% vs. 1.7% vs. 2.4%, p = 0.64) and bradycardia (13.3% vs. 7.7% vs. 9.8%, p = 0.88) between IV sotalol loading for ventricular arrhythmias, PO sotalol initiation for ventricular arrhythmias, and IV sotalol loading for atrial arrhythmias. There were no instances of hypotension, life-threatening ventricular arrhythmias, heart failure, or death. Length of stay was significantly shorter for IV sotalol loading compared to PO sotalol initiation for ventricular arrhythmias (1.1 ± 0.36 days vs. 4.2 ± 1.0 days, p < 0.0001).

CONCLUSION

IV sotalol loading appears feasible and safe for use in ventricular arrhythmias and results in a decreased length of stay. Despite increased comorbidities and greater increase in QTc interval following IV sotalol infusion in the ventricular arrhythmias group, there were no significant differences in successful completion of loading or adverse outcomes when compared to PO sotalol initiation for ventricular arrhythmias and IV loading for atrial arrhythmias.

Long-Term Survival With Implantable Cardioverter-Defibrillator in Different Symptomatic Functional Classes of Heart Failure

The ACC/AHA/HRS (American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society) guidelines recommend implantable cardioverter-defibrillator (ICD) therapy primary prevention in all patients with severely reduced left ventricular ejection fraction (≤30%) regardless of New York Heart Association (NYHA) functional class, whereas recent European guidelines limit the indication to those with symptomatic heart failure (NYHA ≥ II). We therefore aimed to evaluate the long-term survival benefit of primary ICD therapy among postmyocardial infarction patients with and without heart failure (HF) symptoms who were enrolled in MADIT-II (Multicenter Automatic Defibrillator Implantation Trial II). We classified 1,164 MADIT-II patient groups according to the baseline NYHA class (NYHA I [n = 442], NYHA II [n = 425], and NYHA III [n = 297]); patients with NYHA IV were excluded. Multivariate Cox proportional hazards regression modeling was performed to compare the mortality reduction with ICD versus non-ICD therapy during 8 years of follow-up between the 3 NYHA groups. The median (interquartile range) follow-up time was 7.6 (3.5 to 9) years. At 8 years of follow-up, the cumulative probability of mortality in the non-ICD treatment arm was 57% for NYHA I, 57% for NYHA II, and 76% for NYHA III (p <0.001). Multivariate models demonstrated similar long-term mortality risk reduction with ICD compared with the non-ICD treatment arm regardless of HF symptoms: NYHA I (HR = 0.63, 0.46 to 0.85, p = 0.003), NYHA II (HR = 0.68, 0.50 to 0.93, p = 0.017), and NYHA III (HR = 0.68, 0.50 to 0.94, p = 0.018); p for NYHA class by treatment arm interaction >0.10. In conclusion, primary ICD therapy provides consistent long-term survival benefit among patients with previous myocardial infarction and severe left ventricular dysfunction, regardless of HF symptoms.

Stop-codon and C-terminal nonsense mutations are associated with a lower risk of cardiac events in patients with long QT syndrome type 1

BACKGROUND

In long QT syndrome type 1 (LQT1), the location and type of mutations have been shown to affect the clinical outcome. Although haploinsufficiency, including stop-codon and frameshift mutations, has been associated with a lower risk of cardiac events in patients with LQT1, nonsense mutations have been presumed functionally equivalent.

OBJECTIVE

The purpose of this study was to evaluate clinical differences between patients with nonsense mutations.

METHODS

The study sample comprised 1090 patients with genetically confirmed mutations. Patients were categorized into 5 groups, depending on mutation type and location: missense not located in the high-risk cytoplasmic loop (c-loop) (n = 698), which is used as reference; missense c-loop (n = 192); stop-codon (n = 67); frameshift (n = 39); and others (n = 94). The primary outcome was a composite end point of syncope, aborted cardiac arrest, and long QT syndrome-related death (cardiac events). Outcomes were evaluated using the multivariate Cox proportional hazards regression analysis. Standard patch clamp techniques were used.

RESULTS

Compared to patients with missense non-c-loop mutations, the risk of cardiac events was reduced significantly in patients with stop-codon mutations (hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.34-0.96; P = .035), but not in patients with frameshift mutations (HR 1.01; 95% CI 0.58-1.77; P = .97). Our data suggest that currents of the most common stop-codon mutant channel (Q530X) were larger than those of haploinsufficient channels (wild type: 42 ± 6 pA/pF, n = 20; Q530X+wild type: 79 ± 14 pA/pF, n = 20; P < .05) and voltage dependence of activation was altered.

CONCLUSION

Stop-codon mutations are associated with a lower risk of cardiac events in patients with LQT1, while frameshift mutations are associated with the same risk as the majority of the missense mutations. Our data indicate functional differences between these previously considered equivalent mutation subtypes.

Development and preliminary testing of PROGRESS: a Web-based education program for prostate cancer survivors transitioning from active treatment

PURPOSE

This formative research study describes the development and preliminary evaluation of a theory-guided, online multimedia psycho-educational program (PROGRESS) designed to facilitate adaptive coping among prostate cancer patients transitioning from treatment into long-term survivorship.

METHODS

Guided by the Cognitive-Social Health Information Processing Model (C-SHIP) and using health communications best practices, we conducted a two-phase, qualitative formative research study with early stage prostate cancer patients (n = 29) to inform the Web program development. Phase 1 included individual (n = 5) and group (n = 12) interviews to help determine intervention content and interface. Phase 2 employed iterative user/usability testing (n = 12) to finalize the intervention. Interview data were independently coded and collectively analyzed to achieve consensus.

RESULTS

Survivors expressed interest in action-oriented content on (1) managing treatment side effects, (2) handling body image and comorbidities related to overweight/obesity, (3) coping with emotional and communication issues, (4) tips to reduce disruptions of daily living activities, and (5) health skills training tools. Patients also desired the use of realistic and diverse survivor images.

CONCLUSIONS

Incorporation of an established theoretical framework, application of multimedia intervention development best practices, and an evidence-based approach to content and format resulted in a psycho-educational tool that comprehensively addresses survivors' needs in a tailored fashion.

IMPLICATIONS FOR CANCER SURVIVORS

The results suggest that an interactive Web-based multimedia program is useful for survivors if it covers the key topics of symptom control, emotional well-being, and coping skills training; this tool has the potential to be disseminated and implemented as an adjunct to routine clinical care.

A content analysis of self-reported barriers and facilitators to preventing postpartum smoking relapse among a sample of current and former smokers in an underserved population

To characterize the barriers and facilitators thatprevent postpartum relapse and maintain smoking abstinence among a socioeconomically underserved population, recruited through Philadelphia-area women, infants, and children clinics, in-person interviews were conducted with 30 women who had quit smoking for one or more pregnancies in the past 3 years to retrospectively describe their attempts to remain abstinent during the postpartum period. Responses were analysed using the constructs from the Cognitive-Social Health Information Processing model, which identifies the cognitive, affective and behavioral factors involved in goal-oriented self-regulatory actions, in the context of a vulnerable population of women. Motherhood demands were a significant source of relapse stress. Stresses associated with partner and family relationships also contributed to relapse. The presence of other smokers in the environment was mentioned by many women in our sample as affecting their ability to remain smoke-free postpartum. Participants reported four main strategies that helped them to successfully cope with postpartum cravings and relapses, including being informed of smoking risks, maintaining goal-oriented thoughts, focusing on their concerns about the baby's health and receiving positive social support from families and friends. Results provide guidance for the design of smoking relapse interventions that may address the unique stressors reported by underserved postpartum women.