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John, Roy M.

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John

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Roy M.

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John, Roy M.
Author's Publications: search.filters.isAuthorOfPublication.713e9f2f-b835-4366-bc17-ab7860ee10ce

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    Left Atrial Passive Emptying Function Determined by Cardiac Magnetic Resonance Predicts Atrial Fibrillation Recurrence After Pulmonary Vein Isolation
    (Ovid Technologies (Wolters Kluwer Health), 2014) Dodson, John; Neilan, Tomas; Shah, Ravi; Farhad, H.; Blankstein, Ron; Steigner, Michael; Michaud, Gregory F.; John, Roy M.; Abbasi, Siddique Akbar; Jerosch-Herold, Michael; Kwong, Raymond
    Background While pulmonary vein isolation (PVI) has become a mainstream therapy for selected patients with atrial fibrillation (AF), late recurrent AF is common and its risk factors remain poorly defined. The purpose of our study was to test the hypothesis that reduced left atrial passive emptying function (LAPEF) as determined by cardiac magnetic resonance (CMR) has a strong association with late recurrent AF following PVI. Methods and Results 346 AF patients referred for CMR PV mapping prior to PVI were included. Maximum LA volumes (VOLmax) and volumes before atrial contraction (VOLbac) were measured; LAPEF was calculated as (VOLmax − VOLbac)/VOLmax × 100. Kaplan-Meier curves were constructed to determine late recurrent AF stratified by LAPEF quintile. Cox proportional hazards regression was used to adjust for known markers of recurrence. Over a median follow-up of 27 months, 124 patients (35.8%) experienced late recurrent AF. Patients with recurrence were more likely to have non-paroxysmal AF (75.8% vs. 51.4%, P<0.01), higher mean VOLmax (60.2 ml/m2 vs. 52.8 ml/m2, P<0.01), and lower mean LAPEF (19.1% vs. 26.0%, P<0.01). Patients in the lowest LAPEF quintile were at highest risk of developing recurrent AF (two-year recurrence lowest vs. highest: 60.5% vs. 17.3%, P<0.01). After adjusting for known predictors of recurrence, patients with low LAPEF remained significantly more likely to recur (HR lowest vs. highest quintile = 3.92, 95% CI 2.01–7.65). Conclusion We found a strong association between LAPEF and recurrent AF after PVI that persisted after multivariable adjustment.
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    The Incidence, Pattern, and Prognostic Value of Left Ventricular Myocardial Scar by Late Gadolinium Enhancement in Patients With Atrial Fibrillation
    (Elsevier BV, 2013) Neilan, Tomas; Shah, Ravi; Abbasi, Siddique Akbar; Farhad, Hoshang; Groarke, John; Dodson, John; Coelho-Filho, Otavio; McMullan, Ciaran Joseph; Heydari, Bobak; Michaud, Gregory F.; John, Roy M.; van der Geest, Rob; Steigner, Michael; Blankstein, Ron; Jerosch-Herold, Michael; Kwong, Raymond
    Objectives We aimed to identify the frequency, pattern, and prognostic significance of left ventricular (LV) late gadolinium enhancement (LGE) in patients with atrial fibrillation (AF). Background There are limited data on the presence, pattern, and prognostic significance of LV myocardial fibrosis in patients with AF. Late gadolinium enhancement during cardiac magnetic resonance (CMR) is a marker for myocardial fibrosis. Methods We studied a consecutive group of 664 patients without known prior myocardial infarction being referred for radiofrequency ablation of AF. CMR was requested to assess pulmonary venous anatomy. Results Overall, 73% were male, with an average age of 56 years, and an ejection fraction of 55±10%. Left ventricular LGE was found in 88 patients (13%). The endpoint was all-cause mortality, and in this cohort we observed 68 deaths over a median follow-up period of 42 months. On univariable analysis, age (HR 1.05, CI 1.03–1.08, LRχ2 15.2, p=0.0001), diabetes (HR 2.39, CI 1.41–4.09, LRχ210.3, p=0.001), a history of heart failure (HR 1.78, CI 1.09–2.91, LRχ2 5.37, p=0.02), left atrial dimension (HR 1.04, CI 1.01–1.08, LRχ2 6.47, p=0.01), presence of LGE (HR 5.08, CI 3.08–8.36, LRχ2 28.8, p<0.0001), and LGE extent (HR 1.15, CI 1.10–1.21, LRχ2 35.6, p<0.0001) provided the strongest association with mortality. The mortality rate was 8.1% per patient-years in patients with LGE vs. 2.3% patients without LGE. In the best overall multivariable model for mortality, age and the extent of LGE were independent predictors of mortality. Indeed, each 1% increase in LGE associated with a 15% increased risk of death. Conclusions In patients with AF, LV LGE is a frequent finding and is a powerful predictor of mortality.
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    Direct Comparison of Adjacent Endocardial and Epicardial Electrograms: Implications for Substrate Mapping
    (Blackwell Publishing Ltd, 2013) Tokuda, Michifumi; Tedrow, Usha; Inada, Keiichi; Reichlin, Tobias; Michaud, Gregory F.; John, Roy M.; Epstein, Laurence M.; Stevenson, William
    Background: Analysis of unipolar voltage maps has been used to detect epicardial scar, but data to define optimal parameters to identify scar remote from the recording site is limited. This study compares the characteristics of electrograms at endocardial sites adjacent to abnormal epicardial sites. Methods and Results: Data obtained from endocardial and epicardial electroanatomical maps of 31 patients with scar‐related ventricular tachycardia were reviewed. Five hundred twenty‐three pairs of endo‐ and epicardial points were selected according to predefined criteria. The endocardial points adjacent to epicardial scar (bipolar voltage <1.5 mV) had smaller unipolar voltage than those distant from epicardial scar (P<0.001). In multivariable analysis, unipolar voltage was the only endocardial electrogram predictor of epicardial scar (P<0.001, OR 0.94, 95% CI 0.93 to 0.97). An endocardial unipolar amplitude <4.4 mV in the right ventricular (RV) (sensitivity 93%, specificity 76%) and <5.1 mV in the left ventricular (LV) (sensitivity 91%, specificity 75%) was the optimal cutoff predicting epicardial scar. Applying these thresholds to electroanatomical maps, revealed a good match between endocardial unipolar abnormality and epicardial scar for 67% of LV and 75% of RV maps, respectively, but notably poor matches occurred in 8 (29%) maps (7 with nonischemic cardiomyopathy). Site‐by‐site correlations were better for ischemic than nonischemic cardiomyopathy. Conclusions: This study supports the contention that unipolar electrograms are capable of indicating overlying epicardial scar during endocardial mapping, but illustrates limitations that appear to differ with nonischemic as compared to ischemic cardiomyopathy. The presence of epicardial arrhythmia substrate cannot be excluded by analysis of unipolar endocardial maps in some patients.
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    Effect of Late Gadolinium Enhancement on the Recovery of Left Ventricular Systolic Function After Pulmonary Vein Isolation
    (John Wiley and Sons Inc., 2016) Addison, Daniel; Farhad, Hoshang; Shah, Ravi; Mayrhofer, Thomas; Abbasi, Siddique Akbar; John, Roy M.; Michaud, Gregory F.; Jerosch‐Herold, Michael; Hoffmann, Udo; Stevenson, William; Kwong, Raymond; Neilan, Tomas
    Background: The factors that predict recovery of left ventricular (LV) systolic dysfunction among patients with atrial fibrillation (AF) are not completely understood. Late gadolinium enhancement (LGE) of the LV has been reported among patients with AF, and we aimed to test whether the presence LGE was associated with subsequent recovery of LV systolic function among patients with AF and LV dysfunction. Methods and Results: From a registry of 720 consecutive patients undergoing a cardiac magnetic resonance study prior to pulmonary vein isolation (PVI), patients with LV systolic dysfunction (ejection fraction [EF] <50%) were identified. The primary outcome was recovery of LVEF defined as an EF >50%; a secondary outcome was a combined outcome of subsequent heart failure (HF), admission, and death. Of 720 patients, 172 (24%) had an LVEF of <50% prior to PVI. The mean LVEF pre‐PVI was 41±6% (median 43%, range 20% to 49%). Forty‐three patients (25%) had LGE (25 [58%] ischemic), and the extent of LGE was 7.5±4% (2% to 19%). During follow‐up (mean 42 months), 91 patients (53%) had recovery of LVEF, 68 (40%) had early recurrence of AF, 65 (38%) had late AF, 18 (5%) were admitted for HF, and 23 died (13%). Factors associated with nonrecovery of LVEF were older age, history of myocardial infarction, early AF recurrence, late AF recurrence, and LGE. In a multivariable model, the presence of LGE and any recurrence of AF had the strongest association with persistence of LV dysfunction. Additionally, all patients without recurrence of AF and LGE had normalization of LVEF, and recovery of LVEF was associated with reduced HF admissions and death. Conclusions: In patients with AF and LV dysfunction undergoing PVI, the absence of LGE and AF recurrence are predictors of LVEF recovery and LVEF recovery in AF with associated reduction in subsequent death and heart failure.
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