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Kwong, Raymond

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Kwong

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Raymond

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Kwong, Raymond
Author's Publications: search.filters.isAuthorOfPublication.76af6b0a-4837-4545-bcbd-b0ef2213e12d

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    Risk Stratification by Regadenoson Stress Magnetic Resonance Imaging in Patients With Known or Suspected Coronary Artery Disease
    (Elsevier BV, 2014) Abbasi, Siddique Akbar; Heydari, Bobak; Shah, Ravi; Murthy, Venkatesh; Zhang, Ying-Yi; Blankstein, Ron; Steigner, Michael; Jerosch-Herold, Michael; Kwong, Raymond
    The aim of this study was to investigate the association between major adverse cardiovascular events (MACEs) and inducible ischemia on regadenoson cardiac magnetic resonance (CMR) myocardial perfusion imaging (MPI) performed at 3.0 T. Regadenoson stress CMR MPI is increasingly used to assess patients with suspected ischemia; however, its value in patient prognostication and risk reclassification is only emerging. A total of 346 patients with suspected ischemia who were referred for regadenoson CMR were studied. The prognostic association of presence of inducible ischemia by CMR with MACEs was determined. In addition, we assessed the extent of net reclassification improvement by CMR beyond a clinical risk model. There were 52 MACEs during a median follow-up period of 1.9 years. Patients with inducible ischemia were fourfold more likely to experience MACEs (hazard ratio, 4.14, 95% confidence interval 2.37 to 7.24, p <0.0001). In the best overall model, presence of inducible ischemia conferred a 2.6-fold increased hazard for MACEs adjusted to known clinical risk markers (adjusted hazard ratio 2.59, 95% confidence interval 1.30 to 5.18, p = 0.0069). Patients with no inducible ischemia experienced a low rate of cardiac death and myocardial infarction (0.6% per patient-year), whereas those with inducible ischemia had an annual event rate of 3.2%. Net reclassification improvement across risk categories (low <5%, intermediate 5% to 10%, and high >10%) by CMR was 0.29 (95% confidence interval 0.15 to 0.44), and continuous net reclassification improvement was 0.58. In conclusion, in patients with clinical suspicion of myocardial ischemia, regadenoson stress CMR MPI provides robust risk stratification. CMR MPI negative for ischemia was associated with a very low annual rate of hard cardiac events. In addition, CMR MPI provides effective risk reclassification in a substantial proportion of patients.
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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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    Vasodilator Stress Perfusion CMR Imaging Is Feasible and Prognostic in Obese Patients
    (Elsevier BV, 2014) Shah, Ravi; Heydari, Bobak; Coelho-Filho, Otavio; Abbasi, Siddique Akbar; Feng, Jiazhuo H.; Neilan, Tomas; Francis, Sanjeev A.; Blankstein, Ron; Steigner, Michael; Jerosch-Herold, Michael; Kwong, Raymond
    Objectives This study sought to determine feasibility and prognostic performance of stress cardiac magnetic resonance (CMR) in obese patients (body mass index [BMI] ≥30 kg/m2). Background Current stress imaging methods remain limited in obese patients. Given the impact of the obesity epidemic on cardiovascular disease, alternative methods to effectively risk stratify obese patients are needed. Methods Consecutive patients with a BMI ≥30 kg/m2 referred for vasodilating stress CMR were followed for major adverse cardiovascular events (MACE), defined as cardiac death or nonfatal myocardial infarction. Univariable and multivariable Cox regressions for MACE were performed to determine the prognostic association of inducible ischemia or late gadolinium enhancement (LGE) by CMR beyond traditional clinical risk indexes. Results Of 285 obese patients, 272 (95%) completed the CMR protocol, and among these, 255 (94%) achieved diagnostic imaging quality. Mean BMI was 35.4 ± 4.8 kg/m2, with a maximum weight of 200 kg. Reasons for failure to complete CMR included claustrophobia (n = 4), intolerance to stress agent (n = 4), poor gating (n = 4), and declining participation (n = 1). Sedation was required in 19 patients (7%; 2 patients with intravenous sedation). Sixteen patients required scanning by a 70-cm-bore system (6%). Patients without inducible ischemia or LGE experienced a substantially lower annual rate of MACE (0.3% vs. 6.3% for those with ischemia and 6.7% for those with ischemia and LGE). Median follow-up of the cohort was 2.1 years. In a multivariable stepwise Cox regression including clinical characteristics and CMR indexes, inducible ischemia (hazard ratio 7.5; 95% confidence interval: 2.0 to 28.0; p = 0.002) remained independently associated with MACE. When patients with early coronary revascularization (within 90 days of CMR) were censored on the day of revascularization, both presence of inducible ischemia and ischemia extent per segment maintained a strong association with MACE. Conclusions Stress CMR is feasible and effective in prognosticating obese patients, with a very low negative event rate in patients without ischemia or infarction.
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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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    Stress Cardiac Magnetic Resonance Imaging Provides Effective Cardiac Risk Reclassification in Patients With Known or Suspected Stable Coronary Artery Disease
    (Ovid Technologies (Wolters Kluwer Health), 2013) Shah, Ravi; Heydari, Bobak; Coelho-Filho, O.; Murthy, Venkatesh; Abbasi, Siddique Akbar; Feng, J. H.; Pencina, M.; Neilan, Tomas; Meadows, J. L.; Francis, Sanjeev A.; Blankstein, Ron; Steigner, Michael; Di Carli, Marcelo; Jerosch-Herold, Michael; Kwong, Raymond
    Background A recent large-scale clinical trial found that an initial invasive strategy does not improve cardiac outcomes beyond optimized medical therapy in patients with stable coronary artery disease (CAD). Novel methods to stratify at-risk patients may refine therapeutic decisions to improve outcomes. Methods and Results In a cohort of 815 consecutive patients referred for evaluation of myocardial ischemia, we determined the net reclassification improvement of the risk of cardiac death or nonfatal MI (MACE) incremental to clinical risk models, using guideline–based low (<1%), moderate (1–3%), and high (>3%) annual risk categories. In the whole cohort, inducible ischemia demonstrated strong association with MACE (hazard ratio 14.66, P<0.0001) with low negative event rates of MACE and cardiac death (0.6% and 0.4%). This prognostic robustness maintained in patients with prior CAD (hazard ratio 8.17, P<0.0001, and 1.3% and 0.6%, respectively). Adding inducible ischemia to the multivariable clinical risk model (age and prior CAD adjusted) improved discrimination of MACE (C-statistic 0.81 to 0.86, P=0.04; Adjusted hazard ratio 7.37, P<0.0001) and reclassified 91.5% of patients at moderate pre-test risk (65.7% to low risk; 25.8% to high risk) with corresponding changes in the observed event rates (0.3%/year and 4.9%/year, for low and high risk post-test, respectively). Categorical net reclassification index was 0.229 (95% CI 0.063–0.391). Continuous NRI was 1.11 (95% CI 0.81–1.39). Conclusions Stress CMR effectively reclassifies patient risk beyond standard clinical variables, specifically in patients at moderate to high pre-test clinical risk and in patients with prior CAD.
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    Plasma Circulating Extracellular RNAs in Left Ventricular Remodeling Post-Myocardial Infarction
    (Elsevier, 2018) Danielson, Kirsty M.; Shah, Ravi; Yeri, Ashish; Liu, Xiaojun; Camacho Garcia, Fernando; Silverman, Michael; Tanriverdi, Kahraman; Das, Avash; Xiao, Chunyang; Jerosch-Herold, Michael; Heydari, Bobak; Abbasi, Siddique; Van Keuren-Jensen, Kendall; Freedman, Jane E.; Wang, Yaoyu E.; Rosenzweig, Anthony; Kwong, Raymond; Das, Saumya
    Despite substantial declines in mortality following myocardial infarction (MI), subsequent left ventricular remodeling (LVRm) remains a significant long-term complication. Extracellular small non-coding RNAs (exRNAs) have been associated with cardiac inflammation and fibrosis and we hypothesized that they are associated with post-MI LVRm phenotypes. RNA sequencing of exRNAs was performed on plasma samples from patients with “beneficial” (decrease LVESVI ≥ 20%, n = 11) and “adverse” (increase LVESVI ≥ 15%, n = 11) LVRm. Selected differentially expressed exRNAs were validated by RT-qPCR (n = 331) and analyzed for their association with LVRm determined by cardiac MRI. Principal components of exRNAs were associated with LVRm phenotypes post-MI; specifically, LV mass, LV ejection fraction, LV end systolic volume index, and fibrosis. We then investigated the temporal regulation and cellular origin of exRNAs in murine and cell models and found that: 1) plasma and tissue miRNA expression was temporally regulated; 2) the majority of the miRNAs were increased acutely in tissue and at sub-acute or chronic time-points in plasma; 3) miRNA expression was cell-specific; and 4) cardiomyocytes release a subset of the identified miRNAs packaged in exosomes into culture media in response to hypoxia/reoxygenation. In conclusion, we find that plasma exRNAs are temporally regulated and are associated with measures of post-MI LVRm.
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    Weight loss decreases progressive left ventricular remodeling: The Multi-Ethnic Study of Atherosclerosis
    (BioMed Central, 2014) Abbasi, Siddique A; Shah, Ravi; Murthy, Venkatesh L; Eng, John; Wu, Colin; Ouyang, Pamela; Kwong, Raymond; Goldfine, Allison; Bluemke, David; Lima, Joao A; Jerosch-Herold, Michael
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    Myocardial strain imaging with radial acquisitions (SIRA) reduces tag fading compared to Cartesian sampling
    (BioMed Central, 2014) Hulten, Edward; Shah, Ravi; Abbasi, Siddique; Neilan, Tomas; Feng, Jiazuo; Groarke, John; Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond; Jerosch-Herold, Michael
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    Myocardial Tissue Remodeling in Adolescent Obesity
    (Blackwell Publishing Ltd, 2013) Shah, Ravi; Abbasi, Siddique Akbar; Neilan, Tomas; Hulten, Edward; Coelho‐Filho, Otavio; Hoppin, Alison; Levitsky, Lynne; de Ferranti, Sarah; Rhodes, Erinn T.; Traum, Avram; Goodman, Elizabeth; Feng, Henry; Heydari, Bobak; Harris, William S.; Hoefner, Daniel M.; McConnell, Joseph P.; Seethamraju, Ravi; Rickers, Carsten; Kwong, Raymond; Jerosch‐Herold, Michael
    Background: Childhood obesity is a significant risk factor for cardiovascular disease in adulthood. Although ventricular remodeling has been reported in obese youth, early tissue‐level markers within the myocardium that precede organ‐level alterations have not been described. Methods and Results: We studied 21 obese adolescents (mean age, 17.7±2.6 years; mean body mass index [BMI], 41.9±9.5 kg/m2, including 11 patients with type 2 diabetes [T2D]) and 12 healthy volunteers (age, 15.1±4.5 years; BMI, 20.1±3.5 kg/m2) using biomarkers of cardiometabolic risk and cardiac magnetic resonance imaging (CMR) to phenotype cardiac structure, function, and interstitial matrix remodeling by standard techniques. Although left ventricular ejection fraction and left atrial volumes were similar in healthy volunteers and obese patients (and within normal body size‐adjusted limits), interstitial matrix expansion by CMR extracellular volume fraction (ECV) was significantly different between healthy volunteers (median, 0.264; interquartile range [IQR], 0.253 to 0.271), obese adolescents without T2D (median, 0.328; IQR, 0.278 to 0.345), and obese adolescents with T2D (median, 0.376; IQR, 0.336 to 0.407; P=0.0001). ECV was associated with BMI for the entire population (r=0.58, P<0.001) and with high‐sensitivity C‐reactive protein (r=0.47, P<0.05), serum triglycerides (r=0.51, P<0.05), and hemoglobin A1c (r=0.76, P<0.0001) in the obese stratum. Conclusions: Obese adolescents (particularly those with T2D) have subclinical alterations in myocardial tissue architecture associated with inflammation and insulin resistance. These alterations precede significant left ventricular hypertrophy or decreased cardiac function.
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    Correction: Impact of cardiovascular magnetic resonance on management and clinical decision-making in heart failure patients
    (BioMed Central, 2014) Abbasi, Siddique Akbar; Ertel, Andrew; Shah, Ravi; Dandekar, Vineet; Chung, Jaehoon; Bhat, Geetha; Desai, Ankit A; Kwong, Raymond; Farzaneh-Far, Afshin