Browsing by Author "Loring, Zak"

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    ItemOpen Access
    Catheter ablation of atrial fibrillation in patients with diabetes mellitus.
    (Heart rhythm O2, 2020-08) Wang, Allen; Truong, Tracy; Black-Maier, Eric; Green, Cynthia; Campbell, Kristen B; Barnett, Adam S; Febre, Janice; Loring, Zak; Al-Khatib, Sana M; Atwater, Brett D; Daubert, James P; Frazier-Mills, Camille; Hegland, Donald D; Jackson, Kevin P; Jackson, Larry R; Koontz, Jason I; Lewis, Robert K; Pokorney, Sean D; Sun, Albert Y; Thomas, Kevin L; Bahnson, Tristam D; Piccini, Jonathan P

    Background

    Diabetes mellitus (DM) is an independent risk factor for atrial fibrillation (AF). Few studies have compared clinical outcomes after catheter ablation between patients with and those without DM.

    Objective

    The purpose of this study was to compare AF ablation outcomes in patients with and those without DM.

    Methods

    We performed a retrospective analysis of 351 consecutive patients who underwent first-time AF ablation. Clinical outcomes included freedom from recurrent atrial arrhythmia, symptom burden (Mayo AF Symptom Inventory score), cardiovascular and all-cause hospitalizations, and periprocedural complications.

    Results

    Patients with DM (n = 65) were older, had a higher body mass index, more persistent AF, more hypertension, and larger left atrial diameter (P <.05 for all). Median (Q1, Q3) total radiofrequency duration [64.0 (43.6, 81.4) minutes vs 54.3 (39.2, 76.4) minutes; P = .132] and periprocedural complications (P = .868) did not differ between patients with and those without DM. After a median follow-up of 29.5 months, arrhythmia recurrence was significantly higher in the DM group compared to the no-DM group after adjustment for baseline differences (adjusted hazard ratio [HR] 2.24; 95% confidence [CI] 1.42-3.55; P = .001). There was a nonsignificant trend toward higher AF recurrence with worse glycemic levels (HR 1.29; 95% CI 0.99-1.69; P = .064).

    Conclusion

    Although safety outcomes associated with AF ablation were similar between patients with and those without DM, arrhythmia-free survival was significantly lower among patients with DM. Poor glycemic control seems to an important risk factor for AF recurrence.
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    Diagnosis-to-ablation time predicts recurrent atrial fibrillation and rehospitalization following catheter ablation.
    (Heart rhythm O2, 2022-02) Chew, Derek S; Jones, Kelley A; Loring, Zak; Black-Maier, Eric; Noseworthy, Peter A; Exner, Derek V; Packer, Douglas L; Grant, Jennifer; Mark, Daniel B; Piccini, Jonathan P

    Background

    Wait times for catheter ablation in patients with symptomatic atrial fibrillation (AF) may influence clinical outcomes.

    Objective

    This study examined the relationship between the duration from AF diagnosis to ablation, or diagnosis-to-ablation time (DAT), on the clinical response to catheter ablation in a large nationwide cohort of patients.

    Methods

    We identified patients with new AF who underwent catheter ablation between January 2014 and December 2017 using the IBM MarketScan databases. Cox proportional hazard models were used to estimate the strength of the association between DAT and the outcomes of AF recurrence and hospitalization at 1 year postablation.

    Results

    Among 11,143 AF patients who underwent ablation, the median age was 59 years, 31% were female, and the median CHA2DS2-VASc score was 2. Median DAT was 5.5 (2.6, 13.1) months. At 1 year postablation, 10.0% (n = 1116) developed recurrent AF. For each year increase in DAT, the risk of AF recurrence increased by 20% after adjustment for baseline comorbidities and medications (hazard ratio [HR] 1.20, 95% confidence interval [CI] 1.11-1.30). A longer DAT was associated with an increased risk of hospitalization (HR 1.08 per DAT year, 95% CI 1.02-1.15). DAT was a stronger predictor of AF recurrence postablation than traditional clinical risk factors, including age, prior heart failure, or renal failure.

    Conclusion

    Increasing duration between AF diagnosis and catheter ablation is associated with higher AF recurrence rates and all-cause hospitalization. Our findings are consistent with a growing body of evidence supporting the benefits of prioritizing early restoration of sinus rhythm.
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    Frequency and causes of QRS prolongation during exercise electrocardiogram testing in biventricular paced patients with heart failure.
    (HeartRhythm case reports, 2020-06) Atwater, Brett D; Emerek, Kasper; Loring, Zak; Polcwiartek, Christoffer; Jackson, Kevin P; Friedman, Daniel J
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    Healthcare-seeking behaviour, barriers to care and predictors of symptom improvement among patients with cardiovascular disease in northern Tanzania.
    (International health, 2019-12-15) Hertz, Julian T; Sakita, Francis M; Kweka, Godfrey L; Loring, Zak; Thielman, Nathan M; Temu, Gloria; Bartlett, John A

    Background

    Little is known about healthcare-seeking behaviour and barriers to care for cardiovascular disease (CVD) in sub-Saharan Africa.

    Methods

    Emergency department patients in Tanzania with acute CVD were prospectively enrolled. Questionnaires were administered at enrollment and 30 d later.

    Results

    Of 241 patients, 186 (77.2%) had visited another facility for the same illness episode (median symptom duration prior to presentation was 7 d) and 82 (34.0%) reported that they were initially unaware of the potential seriousness of their symptoms. Of the 208 (86.3%) patients completing follow-up, 16 (7.7%) had died, 38 (18.3%) had visited another facility for persistent symptoms, 99 (47.6%) felt they understood their diagnosis, 87 (41.8%) felt they understood their treatment and 11 (7.8%) could identify any of their medications. Predictors of 30 d survival with symptom improvement included medication compliance (p<0.001), understanding the diagnosis (p=0.007), understanding the treatment (p<0.001) and greater CVD knowledge (p=0.008).

    Conclusions

    Patients with CVD in Tanzania usually visit multiple facilities for the same illness episode, typically after prolonged delays. Only a minority understand their diagnosis and treatment, and such understanding is correlated with survival with symptom improvement. Patient-centred interventions are needed to improve the quality of cardiovascular care in Tanzania.
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    Noninvasive electrocardiographic mapping of ventricular tachycardia in a patient with a left ventricular assist device.
    (HeartRhythm case reports, 2020-07) Rehorn, Michael R; Koontz, Jason; Barnett, Adam S; Black-Maier, Eric; Piccini, Jonathan P; Loring, Zak; Schroder, Jacob; Sun, Albert Y
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    Patterns of Emergency Care for Possible Acute Coronary Syndrome Among Patients with Chest Pain or Shortness of Breath at a Tanzanian Referral Hospital.
    (Global heart, 2020-02-06) Hertz, Julian T; Kweka, Godfrey L; Bloomfield, Gerald S; Limkakeng, Alexander T; Loring, Zak; Temu, Gloria; Mmbaga, Blandina T; Gerardo, Charles J; Sakita, Francis M
    Background:Acute coronary syndrome (ACS) is thought to be a rare diagnosis in sub-Saharan Africa, but little is known about diagnostic practices for patients with possible ACS symptoms in the region. Objective:To describe current care practices for patients with ACS symptoms in Tanzania to identify factors that may contribute to ACS under-detection. Methods:Emergency department patients with chest pain or shortness of breath at a Tanzanian referral hospital were prospectively observed. Medical histories were obtained, and diagnostic workups, treatments, and diagnoses were recorded. Five-year risk of cardiovascular events was calculated via the Harvard National Health and Nutrition Examination Survey risk score. Telephone follow-ups were conducted 30 days after enrollment. Results:Of 339 enrolled patients, the median (IQR) age was 60 (46, 72) years, 252 (74.3%) had hypertension, and 222 (65.5%) had >10% five-year risk of cardiovascular event. The median duration of symptoms prior to presentation was 7 days, and 314 (92.6%) reported symptoms worsened by exertion. Of participants, 170 (50.1%) received an electrocardiogram, and 9 (2.7%) underwent cardiac biomarker testing. There was no univariate association between five-year cardiovascular risk and decision to obtain an electrocardiogram (p = 0.595). The most common physician-documented diagnoses were symptomatic hypertension (104 patients, 30.7%) and heart failure (99 patients, 29.2%). Six patients (1.8%) were diagnosed with ACS, and 3 (0.9%) received aspirin. Among 284 (83.8%) patients completing 30-day follow-up, 20 (7.0%) had died. Conclusions:Many patients with ACS risk factors present to the emergency department of a Tanzanian referral hospital with possible ACS symptoms, but marked delays in care-seeking are common. Complete diagnostic workups for ACS are uncommon, ACS is rarely diagnosed or treated with evidence-based therapies, and mortality in patients with these symptoms is high. Physician practices may be contributing to ACS under-detection in Tanzania, and interventions are needed to improve ACS care.
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    Predicting atrial fibrillation recurrence after ablation in patients with heart failure: Validity of the APPLE and CAAP-AF risk scoring systems.
    (Pacing and clinical electrophysiology : PACE, 2019-11) Black-Maier, Eric; Parish, Alice; Steinberg, Benjamin A; Green, Cynthia L; Loring, Zak; Barnett, Adam S; Al-Khatib, Sana M; Atwater, Brett D; Daubert, James P; Frazier-Mills, Camille; Hegland, Donald D; Jackson, Kevin P; Jackson, Larry R; Koontz, Jason; Lewis, Robert K; Pokorney, Sean D; Sun, Albert Y; Thomas, Kevin L; Bahnson, Tristam D; Piccini, Jonathan P

    Background

    Compared with medical therapy, catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) improves cardiovascular outcomes. Risk scores (CAAP-AF and APPLE) have been developed to predict the likelihood of AF recurrence after ablation, have not been validated specifically in patients with AF and HF.

    Methods

    We analyzed baseline characteristics, risk scores, and rates of AF recurrence 12 months postablation in a cohort of 230 consecutive patients with AF and HF undergoing PVI in the Duke Center for Atrial Fibrillation registry from 2009-2013.

    Results

    During a follow-up period of 12 months, 76 of 230 (33%) patients with HF experienced recurrent AF after ablation. The median APPLE and CAAP-AF scores were 1.5 ([Q1, Q3]: [1.0, 2.0]) and 4.0 ([Q1, Q3]: [3.0, 5.0]), respectively and were not different from those patients with and without recurrent AF. Freedom from AF was not different according to APPLE and CAAP-AF scores. Discrimination for recurrent AF with the CAAP-AF score was modest with a C-statistic of 0.60 (95% CI 0.52-0.67). Discrimination with the APPLE score was similarly modest, with a C-statistic of 0.54 (95% CI: 0.47-0.62).

    Conclusions

    Validated predictive risk scores for recurrent AF after catheter ablation exhibit limited predictive ability in cohorts of AF and HF. Additional tools are needed to facilitate risk stratification and patient selection for AF ablation in patients with concomitant HF.
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    The prevalence, management, and thirty-day outcomes of symptomatic atrial fibrillation in a Tanzanian emergency department.
    (African journal of emergency medicine : Revue africaine de la medecine d'urgence, 2021-12) Oyediran, Isaac O; Prattipati, Sainikitha; Sakita, Francis M; Kweka, Godfrey L; Tarimo, Tumsifu G; Peterson, Timothy; Loring, Zak; Limkakeng, Alexander T; Bloomfield, Gerald S; Hertz, Julian T

    Introduction

    Data describing atrial fibrillation (AF) care in emergency centres (ECs) in sub-Saharan Africa is lacking. We sought to describe the prevalence and outcomes of AF in a Tanzanian EC.

    Methods

    In a prospective, observational study, adults presenting with chest pain or shortness of breath to a Tanzanian EC were enrolled from January through October 2019. Participants underwent electrocardiogram testing which were reviewed by two independent physician judges to determine presence of AF. Participants were asked about their medical history and medication use at enrollment, and a follow-up questionnaire was administered via telephone thirty days later to assess mortality, interim stroke, and medication use.

    Results

    Of 681 enrolled patients, 53 (7.8%) had AF. The mean age of participants with AF was 68.1, with a standard deviation (sd) of 21.1 years, and 23 of the 53 (43.4%) being male. On presentation, none of the participants found to have AF reported a previous history of AF. The median CHADS-VASC score among participants was 4 with an interquartile range (IQR) of 2-4. No participants were taking an anticoagulant at baseline. On index presentation, 49 (92.5%) participants with AF were hospitalised with 52 (98.1%) participants completing 30-day follow-up. 18 (34%) participants died, and 5 (9.6%) suffered a stroke. Of the surviving 31 participants with AF and a CHADS-VASC score ≥ 2, none were taking other anti-coagulants at 30 days. Compared to participants without AF, participants with AF were more likely to be hospitalised (OR 5.25, 95% CI 2.10-17.95, p < 0.001), more likely to die within thirty days (OR 1.93, 95% CI 1.03-3.50, p = 0.031), and more likely to suffer a stroke within thirty days (OR 5.91, 95% CI 1.76-17.28, p < 0.001).

    Discussion

    AF is common in a Tanzanian EC, with thirty-day mortality being high, but use of evidence-based therapies is rare. There is an opportunity to improve AF care and outcomes in Tanzania.
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    VVI pacing with normal QRS duration and ventricular function: MOST trial findings relevant to leadless pacemakers.
    (Pacing and clinical electrophysiology : PACE, 2020-12) Loring, Zak; North, Rebecca; Hellkamp, Anne S; Atwater, Brett D; Frazier-Mills, Camille G; Jackson, Kevin P; Pokorney, Sean D; Lamas, Gervasio A; Piccini, Jonathan P

    Background

    Leadless pacemakers (LPs) provide ventricular pacing without the risks associated with transvenous leads and device pockets. LPs are appealing for patients who need pacing, but do not need defibrillator or cardiac resynchronization therapy. Most implanted LPs provide right ventricular pacing without atrioventricular synchrony (VVIR mode). The Mode Selection Trial in Sinus Node Dysfunction (MOST) showed similar outcomes in patients randomized to dual-chamber (DDDR) versus ventricular pacing (VVIR). We compared outcomes by pacing mode in LP-eligible patients from MOST.

    Methods

    Patients enrolled in the MOST study with an left ventricular ejection fraction (LVEF) >35%, QRS duration (QRSd) <120 ms and no history of ventricular arrhythmias or prior implantable cardioverter defibrillators were included (LP-eligible population). Cox proportional hazards models were used to test the association between pacing mode and death, stroke or heart failure (HF) hospitalization and atrial fibrillation (AF).

    Results

    Of the 2010 patients enrolled in MOST, 1284 patients (64%) met inclusion criteria. Baseline characteristics were well balanced across included patients randomized to DDDR (N = 630) and VVIR (N = 654). Over 4 years of follow-up, there was no association between pacing mode and death, stroke or HF hospitalization (VVIR HR 1.28 [0.92-1.75]). VVIR pacing was associated with higher risk of AF (HR 1.32 [1.08-1.61], P = .007), particularly in patients with no history of AF (HR 2.38 [1.52-3.85], P < .001).

    Conclusion

    In patients without reduced LVEF or prolonged QRSd who would be eligible for LP, DDDR, and VVIR pacing demonstrated similar rates of death, stroke or HF hospitalization; however, VVIR pacing significantly increased the risk of AF development.