Browsing by Author "Tamarappoo, Balaji"

Now showing 1 - 6 of 6
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    Computed tomography angiography-derived extracellular volume fraction predicts early recovery of left ventricular systolic function after transcatheter aortic valve replacement
    (Oxford University Press, 2021) Han, Donghee; Tamarappoo, Balaji; Klein, Eyal; Tyler, Jeffrey; Chakravarty, Tarun; Otaki, Yuka; Miller, Robert; Eisenberg, Evann; Park, Rebekah; Singh, Siddharth; Shiota, Takahiro; Siegel, Robert; Stegic, Jasminka; Salseth, Tracy; Cheng, Wen; Dey, Damini; Thomson, Louise; Berman, Daniel; Makkar, Raj; Friedman, John; Radiation Oncology, School of Medicine
    Aims: Recovery of left ventricular ejection fraction (LVEF) after aortic valve replacement has prognostic importance in patients with aortic stenosis (AS). The mechanism by which myocardial fibrosis impacts LVEF recovery in AS is not well characterized. We sought to evaluate the predictive value of extracellular volume fraction (ECV) quantified by cardiac CT angiography (CTA) for LVEF recovery in patients with AS after transcatheter aortic valve replacement (TAVR). Methods and results: In 109 pre-TAVR patients with LVEF <50% at baseline echocardiography, CTA-derived ECV was calculated as the ratio of change in CT attenuation of the myocardium and the left ventricular (LV) blood pool before and after contrast administration. Early LVEF recovery was defined as an absolute increase of ≥10% in LVEF measured by post-TAVR follow-up echocardiography within 6 months of the procedure. Early LVEF recovery was observed in 39 (36%) patients. The absolute increase in LVEF was 17.6 ± 8.8% in the LVEF recovery group and 0.9 ± 5.9% in the no LVEF recovery group (P < 0.001). ECV was significantly lower in patients with LVEF recovery compared with those without LVEF recovery (29.4 ± 6.1% vs. 33.2 ± 7.7%, respectively, P = 0.009). In multivariable analysis, mean pressure gradient across the aortic valve [odds ratio (OR): 1.07, 95% confidence interval (CI): 1.03-1.11, P: 0.001], LV end-diastolic volume (OR: 0.99, 95% CI: 0.98-0.99, P: 0.035), and ECV (OR: 0.92, 95% CI: 0.86-0.99, P: 0.018) were independent predictors of early LVEF recovery. Conclusion: Increased myocardial ECV on CTA is associated with impaired LVEF recovery post-TAVR in severe AS patients with impaired LV systolic function.
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    Intracoronary acetylcholine for vasospasm provocation in women with ischemia and no obstructive coronary artery disease
    (Elsevier, 2025-03-18) Tjoe, Benita; Pacheco, Christine; Suppogu, Nissi; Samuels, Bruce; Rezaeian, Panteha; Tamarappoo, Balaji; Berman, Daniel S.; Sharif, Behzad; Nelson, Michael; Anderson, R. David; Petersen, John; Pepine, Carl J.; Thomson, Louise E. J.; Merz, C. Noel Bairey; Wei, Janet; Radiology and Imaging Sciences, School of Medicine
    Objectives: To evaluate the utility of higher dose intracoronary acetylcholine (ACh) during invasive coronary function testing (CFT) in women with suspected ischemia and no obstructive coronary artery disease (INOCA) for detection of epicardial vasospasm, relation to quality of life (QoL) and the presence of scar by late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMRI). Background: CFT is an established method for diagnosis of coronary microvascular dysfunction (CMD). The utility of epicardial vasospasm provocation testing with higher dose ACh infusion is not fully understood. Methods: Women with suspected INOCA undergoing invasive CFT were enrolled in the Women's Ischemia Syndrome Evaluation-Pre-Heart Failure with Preserved Ejection Fraction (WISE Pre-HFpEF) study (NCT03876223). Incremental infusions of 0.364, 36.4 μg and 108 μg ACh were used for vasospasm provocation. Vasospasm was defined as ≥75 % artery diameter reduction compared to post-nitroglycerin diameter and related to QoL and LGE on CMRI. Results: Among 73 women (56 ± 11 years), epicardial vasospasm was detected in 17 (23 %). Among women with vasospasm, the vast majority (94 %) had coronary endothelial dysfunction and few (12 %) had other abnormal CFT measures. Those with vasospasm had more nocturnal angina symptoms, calcium channel blocker use, poorer QoL (all p = 0.001) and disease perception (p = 0.02) than those without. LGE scar by CMRI was not associated with vasospasm (p = 0.22). Conclusions: Among women with suspected INOCA, intracoronary Ach spasm testing provoked epicardial vasospasm in one fourth. Women with epicardial vasospasm overwhelmingly had concomitant endothelial dysfunction, worse QoL but not more frequent myocardial scar on CMRI.
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    Intramyocardial hemorrhage drives fatty degeneration of infarcted myocardium
    (Springer Nature, 2022-10-27) Cokic, Ivan; Chan, Shing Fai; Guan, Xingmin; Nair, Anand R.; Yang, Hsin-Jung; Liu, Ting; Chen, Yinyin; Hernando, Diego; Sykes, Jane; Tang, Richard; Butler, John; Dohnalkova, Alice; Kovarik, Libor; Finney, Robert; Kali, Avinash; Sharif, Behzad; Bouchard, Louis S.; Gupta, Rajesh; Krishnam, Mayil Singaram; Vora, Keyur; Tamarappoo, Balaji; Howarth, Andrew G.; Kumar, Andreas; Francis, Joseph; Reeder, Scott B.; Wood, John C.; Prato, Frank S.; Dharmakumar, Rohan; Medicine, School of Medicine
    Sudden blockage of arteries supplying the heart muscle contributes to millions of heart attacks (myocardial infarction, MI) around the world. Although re-opening these arteries (reperfusion) saves MI patients from immediate death, approximately 50% of these patients go on to develop chronic heart failure (CHF) and die within a 5-year period; however, why some patients accelerate towards CHF while others do not remains unclear. Here we show, using large animal models of reperfused MI, that intramyocardial hemorrhage - the most damaging form of reperfusion injury (evident in nearly 40% of reperfused ST-elevation MI patients) - drives delayed infarct healing and is centrally responsible for continuous fatty degeneration of the infarcted myocardium contributing to adverse remodeling of the heart. Specifically, we show that the fatty degeneration of the hemorrhagic MI zone stems from iron-induced macrophage activation, lipid peroxidation, foam cell formation, ceroid production, foam cell apoptosis and iron recycling. We also demonstrate that timely reduction of iron within the hemorrhagic MI zone reduces fatty infiltration and directs the heart towards favorable remodeling. Collectively, our findings elucidate why some, but not all, MIs are destined to CHF and help define a potential therapeutic strategy to mitigate post-MI CHF independent of MI size.
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    Left ventricular circumferential strain and coronary microvascular dysfunction: A report from the Women’s Ischemia Syndrome Evaluation Coronary Vascular Dysfunction (WISE-CVD) Project
    (Elsevier, 2021) Tamarappoo, Balaji; Samuel, T. Jake; Elboudwarej, Omeed; Thomson, Louise E. J.; Aldiwani, Haider; Wei, Janet; Mehta, Puja; Cheng, Susan; Sharif, Behzad; AlBadri, Ahmed; Handberg, Eileen M.; Petersen, John; Pepine, Carl J.; Nelson, Michael D.; Bairey Merz, C. Noel; Graduate Medical Education, School of Medicine
    Aims: Women with ischemia but no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD). Left ventricular (LV) circumferential strain (CS) is often lower in INOCA compared to healthy controls; however, it remains unclear whether CS differs between INOCA women with and without CMD. We hypothesized that CS would be lower in women with CMD, consistent with CMD-induced LV mechanical dysfunction. Methods and results: Cardiac magnetic resonance (cMR) images were examined from women enrolled in the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction Project. CS by feature tracking in INOCA women with CMD, defined as myocardial perfusion reserve index (MPRI) <1.84 during adenosine-stress perfusion cMR, was compared with CS in women without CMD. In a subset who had invasive coronary function testing (CFT), the relationship between CS and CFT metrics, LV ejection fraction (LVEF) and cardiovascular risk factors was investigated. Among 317 women with INOCA, 174 (55%) had CMD measured by MPRI. CS was greater in women with CMD compared to those without CMD (23.2 ± 2.5% vs. 22.1 ± 3.0%, respectively, P = 0.001). In the subset with CFT (n = 153), greater CS was associated with increased likelihood of reduced vasodilator capacity (OR = 1.33, 95%CI = 1.02-1.72, p = 0.03) and discriminated abnormal vs. normal coronary vascular function compared to CAD risk factors, LVEF and LV concentricity (AUC: 0.82 [0.73-0.96 95%CI] vs. 0.65 [0.60-0.71 95%CI], respectively, P = 0.007). Conclusion: The data indicate that LV circumferential strain is related to and predicts CMD, although in a direction contrary with our hypothesis, which may represent an early sign of LV mechanical dysfunction in CMD.
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    Reduced myocardial perfusion is common among subjects with ischemia and no obstructive coronary artery disease and heart failure with preserved ejection fraction: a report from the WISE-CVD continuation study
    (OAE, 2022) Aldiwani, Haider; Nelson, Michael D.; Sharif, Behzad; Wei, Janet; Samuel, T. Jake; Suppogu, Nissi; Quesada, Odayme; Cook-Wiens, Galen; Gill, Edward; Szczepaniak, Lidia S.; Thomson, Louise E. J.; Tamarappoo, Balaji; Asif, Anum; Shufelt, Chrisandra; Berman, Daniel; Merz, C. Noel Bairey; Medicine, School of Medicine
    Aim: Women with evidence of ischemia and no obstructive coronary artery disease (INOCA) have an increased risk of major adverse cardiac events, including heart failure with preserved ejection fraction (HFpEF). To investigate potential links between INOCA and HFpEF, we examined pathophysiological findings present in both INOCA and HFpEF. Methods: We performed adenosine stress cardiac magnetic resonance imaging (CMRI) in 56 participants, including 35 women with suspected INOCA, 13 women with HFpEF, and 8 reference control women. Myocardial perfusion imaging was performed at rest and with vasodilator stress with intravenous adenosine. Myocardial perfusion reserve index was quantified as the ratio of the upslope of increase in myocardial contrast at stress vs. rest. All CMRI measures were quantified using CVI42 software (Circle Cardiovascular Imaging Inc). Statistical analysis was performed using linear regression models, Fisher's exact tests, ANOVA, or Kruskal-Wallis tests. Results: Age (P = 0.007), Body surface area (0.05) were higher in the HFpEF group. Left ventricular ejection fraction (P = 0.02) was lower among the INOCA and HFpEF groups than reference controls after age adjustment. In addition, there was a graded reduction in myocardial perfusion reserve index in HFpEF vs. INOCA vs. reference controls (1.5 ± 0.3, 1.8 ± 0.3, 1.9 ± 0.3, P = 0.02), which was attenuated with age-adjustment. Conclusion: Reduced myocardial perfusion reserve appears to be a common pathophysiologic feature in INOCA and HFpEF patients.
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    Sex differences in computed tomography angiography-derived coronary plaque burden in relation to invasive fractional flow reserve
    (Elsevier, 2023) Han, Donghee; van Diemen, Pepijn; Kuronuma, Keiichiro; Lin, Andrew; Motwani, Manish; McElhinney, Priscilla; Flores Tomasino, Guadalupe; Park, Caroline; Kwan, Alan; Tzolos, Evangelos; Klein, Eyal; Grodecki, Kajetan; Shou, Benjamin; Tamarappoo, Balaji; Cadet, Sebastien; Danad, Ibrahim; Driessen, Roel S.; Berman, Daniel S.; Slomka, Piotr J.; Dey, Damini; Knaapen, Paul; Medicine, School of Medicine
    Background: Distinct sex-related differences exist in coronary artery plaque burden and distribution. We aimed to explore sex differences in quantitative plaque burden by coronary CT angiography (CCTA) in relation to ischemia by invasive fractional flow reserve (FFR). Methods: This post-hoc analysis of the PACIFIC trial included 581 vessels in 203 patients (mean age 58.1 ​± ​8.7 years, 63.5% male) who underwent CCTA and per-vessel invasive FFR. Quantitative assessment of total, calcified, non-calcified, and low-density non-calcified plaque burden were performed using semiautomated software. Significant ischemia was defined as invasive FFR ≤0.8. Results: The per-vessel frequency of ischemia was higher in men than women (33.5% vs. 7.5%, p ​< ​0.001). Women had a smaller burden of all plaque subtypes (all p ​< ​0.01). There was no sex difference on total, calcified, or non-calcified plaque burdens in vessels with ischemia; only low-density non-calcified plaque burden was significantly lower in women (beta: -0.183, p ​= ​0.035). The burdens of all plaque subtypes were independently associated with ischemia in both men and women (For total plaque burden (5% increase): Men, OR: 1.15, 95%CI: 1.06-1.24, p ​= ​0.001; Women, OR: 1.96, 95%CI: 1.11-3.46, p ​= ​0.02). No significant interaction existed between sex and total plaque burden for predicting ischemia (interaction p ​= ​0.108). The addition of quantitative plaque burdens to stenosis severity and adverse plaque characteristics improved the discrimination of ischemia in both men and women. Conclusions: In symptomatic patients with suspected CAD, women have a lower CCTA-derived burden of all plaque subtypes compared to men. Quantitative plaque burden provides independent and incremental predictive value for ischemia, irrespective of sex.