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Featured researches published by William O. Ntim.


Journal of Clinical Oncology | 2010

Aortic Stiffness Increases Upon Receipt of Anthracycline Chemotherapy

Narumol Chaosuwannakit; Ralph B. D'Agostino; Craig A. Hamilton; Kimberly Lane; William O. Ntim; Julia Lawrence; Susan A. Melin; Leslie R. Ellis; Frank M. Torti; William C. Little; W. Gregory Hundley

PURPOSE Cancer survivors exposed to anthracyclines experience an increased risk of cardiovascular (CV) events. We hypothesized that anthracycline use may increase aortic stiffness, a known predictor of CV events. PATIENTS AND METHODS We performed a prospective, case-control study involving 53 patients: 40 individuals who received an anthracycline for the treatment of breast cancer, lymphoma, or leukemia (cases), and 13 age- and sex-matched controls. Each participant underwent phase-contrast cardiovascular magnetic resonance measures of pulse wave velocity (PWV) and aortic distensibility (AoD) in the thoracic aorta at baseline, and 4 months after initiation of chemotherapy. Four one-way analyses of covariance models were fit in which factors known to influence thoracic aortic stiffness were included as covariates in the models. Results At the 4-month follow-up visit, aortic stiffness remained similar to baseline in the control participants. However, in the participants receiving anthracyclines, aortic stiffness increased markedly (relative to baseline), as evidenced by a decrease in AoD (P < .0001) and an increase in PWV (P < .0001). These changes in aortic stiffness persisted after accounting for age, sex, cardiac output, administered cardioactive medications, and underlying clinical conditions known to influence aortic stiffness, such as hypertension or diabetes (P < .0001). CONCLUSION A significant increase in aortic stiffness occurs within 4 months of exposure to an anthracycline which was not seen in an untreated control group. These results indicate that previously regarded cardiotoxic cancer therapy adversely increases thoracic aortic stiffness, a known independent predictor of adverse cardiovascular events.


Journal of the American College of Cardiology | 2008

Prediction of Cardiac Events in Patients With Reduced Left Ventricular Ejection Fraction With Dobutamine Cardiovascular Magnetic Resonance Assessment of Wall Motion Score Index

Erica Dall'Armellina; Timothy M. Morgan; Sangeeta Mandapaka; William O. Ntim; J. Jeffrey Carr; Craig A. Hamilton; John R. Hoyle; Hollins P. Clark; Paige B. Clark; Kerry M. Link; Doug Case; W. Gregory Hundley

OBJECTIVES The purpose of this study was to assess the utility of dobutamine cardiovascular magnetic resonance (DCMR) results for predicting cardiac events in individuals with reduced left ventricular ejection fraction (LVEF). BACKGROUND It is unknown whether DCMR results identify a poor cardiac prognosis when the resting LVEF is moderately to severely reduced. METHODS Two hundred consecutive patients ages 30 to 88 (average 64) years with an LVEF <or=55% that were poorly suited for stress echocardiography underwent DCMR in which left ventricular wall motion score index (WMSI), defined as the average wall motion of the number of segments scored, was assessed at rest, during low-dose, and after peak intravenous infusion of dobutamine/atropine. All participants were followed for an average of 5 years after DCMR to ascertain the post-testing occurrence of cardiac death, myocardial infarction (MI), and unstable angina or congestive heart failure warranting hospital stay. RESULTS After accounting for risk factors associated with coronary arteriosclerosis and MI, a stress-induced increase in WMSI during DCMR was associated with future cardiac events (p < 0.001). A DCMR stress-induced change in WMSI added significantly to predicting future cardiac events (p = 0.003), after accounting for resting LVEF, but this predictive value was confined primarily to those with an LVEF >40%. CONCLUSIONS In individuals with mild to moderate reductions in LVEF (40% to 55%), dobutamine-induced increases in WMSI forecast MI and cardiac death to a greater extent than an assessment of resting LVEF. In those with an LVEF <40%, a dobutamine-induced increase in WMSI does not predict MI and cardiac death beyond the assessment of resting LVEF.


Jacc-cardiovascular Imaging | 2009

Dobutamine cardiac magnetic resonance results predict cardiac prognosis in women with known or suspected ischemic heart disease.

Eric L. Wallace; Timothy M. Morgan; Thomas F. Walsh; Erica Dall'Armellina; William O. Ntim; Craig A. Hamilton; W. Gregory Hundley

OBJECTIVES The purpose of this study was to determine the prognostic utility of dobutamine cardiac magnetic resonance (DCMR) stress test results in women. BACKGROUND To date, the preponderance of studies reporting the utility of DCMR stress results for predicting cardiac prognosis have been performed in men. We sought to determine the utility of DCMR results for predicting cardiac prognosis in women. METHODS Two hundred sixty-six consecutively referred women underwent DCMR in which left ventricular wall motion (LVWM) was assessed at rest and after intravenous dobutamine and atropine. Inducible LVWM abnormalities were identified during testing. Women were contacted to determine the post-DCMR occurrence of a cardiac event. All events were substantiated according to defined criteria and then were verified after a thorough medical record review by individuals blinded to testing data. RESULTS Women were contacted an average of 6.2 +/- 1.6 (median 6.2, range 0.8 to 10.4) years after DCMR; 27% of the women experienced an inducible LVWM abnormality during testing. In those with and without inducible LVWM abnormalities, the proportion of women with cardiac events were 63% versus 30%, respectively, (hazard ratio [HR]: 2.7; 95% confidence interval [CI]: 1.8 to 4.3 for the presence of inducible LVWM abnormalities p < 0.0001). The proportion of women with myocardial infarction (MI) and cardiac death were 33.3% and 7.5%, respectively. This resulted in a HR for MI and cardiac death of 4.1 (95% CI: 2.2 to 9.4) for those with versus those without inducible LVWM abnormalities; p < 0.0001. A subgroup analysis was performed in women without a history of coronary artery disease and in those with LVWM abnormalities, DCMR remained an adverse predictor of cardiac events (HR: 4.0, 95% CI: 1.8 to 9.0, p = 0.003). CONCLUSIONS Inducible LVWM abnormalities during DCMR predict cardiac death and MI in women. Similar to men, these results indicate that DCMR is a valuable noninvasive stress imaging modality for identifying cardiac risk in women with known or suspected ischemic heart disease.


Circulation-cardiovascular Imaging | 2010

Left ventricular hypertrophy influences cardiac prognosis in patients undergoing dobutamine cardiac stress testing.

Charaslak Charoenpanichkit; Timothy M. Morgan; Craig A. Hamilton; Eric L. Wallace; Killian Robinson; William O. Ntim; W. Gregory Hundley

Background—This study was performed to determine the utility of dobutamine stress test results for predicting myocardial infarction (MI) and cardiac death in patients with chest pain and left ventricular hypertrophy (LVH). Methods and Results—Three hundred fifty-three participants with a mean±SD age of 64±12 years (54% men) underwent dobutamine cardiovascular magnetic resonance stress testing and then were followed up for 6±2 years (mean±SD; range, 0.5–11.5) to assess the post–dobutamine cardiovascular magnetic resonance stress test occurrence of MI or cardiac death. LV mass and the presence or absence of ischemia were determined; LVH was defined as an LV mass index >96 g/m2 in men and >77 g/m2 in women. LVH was present in 62 participants (18% of the men and 17% of the women, P=0.90). Seventy-one (20%) participants experienced an MI or cardiac death during follow-up. The MI and cardiac death rate was more frequent in those with versus without LVH (32% vs 17%, P=0.009). In multivariable analysis that accounted for the presence of preexisting coronary artery disease, hypertension, diabetes, stress-induced ischemia, and reduced LV ejection fraction, LVH was an independent predictor of MI and cardiac death (hazard ratio=1.99; 95% CI, 1.13–3.50; P=0.02). Conclusions—LVH is predictive of future MI and cardiac death in patients with or without inducible ischemia during dobutamine cardiac stress testing. As a result, LVH should be reported in those referred for dobutamine cardiac stress tests, particularly in those without inducible ischemia, in whom one would otherwise assume a favorable cardiac prognosis.


Journal of Computer Assisted Tomography | 2009

Left ventricular infarct size assessed with 0.1 mmol/kg of gadobenate dimeglumine correlates with that assessed with 0.2 mmol/kg of gadopentetate dimeglumine.

Monravee Tumkosit; Chirapa Puntawangkoon; Timothy M. Morgan; Hollins P. Clark; Craig A. Hamilton; William O. Ntim; Paige B. Clark; W. Gregory Hundley

Objective: To determine myocardial infarct (MI) size during cardiovascular magnetic resonance at 1.5 Tesla using 0.1 mmol/kg body weight of gadobenate dimeglumine (Gd-BOPTA) and 0.2 mmol/kg body weight of gadopentetate dimeglumine (Gd-DTPA). Methods: Twenty participants (16 men, 4 women), aged 58 ± 12 years, with a prior chronic MI were imaged in a crossover design. Participants received 0.2 mmol/kg body weight of Gd-DTPA and 0.1 mmol/kg body weight of Gd-BOPTA on 2 occasions separated by 3 to 7 days. Results: The correlations were high between Gd-DTPA and Gd-BOPTA measures of infarct volume (r = 0.93) and the percentage of infarct relative to left ventricular myocardial volume (r = 0.85). The size and location of the infarcts were similar (P = 0.9) for the 2 contrast agents. Interobserver correlation of infarct volume (r = 0.91) was high. Conclusions: In chronic MI, late gadolinium enhancement identified with a single 0.1 mmol/kg body weight dose of Gd-BOPTA is associated in volume and location to a double (0.2 mmol/kg body weight) dose of Gd-DTPA. Lower doses of higher relaxivity contrast agents should be considered for determining left ventricular myocardial infarct size.


Journal of Cardiovascular Magnetic Resonance | 2009

Adverse effect of increased left ventricular wall thickness on five year outcomes of patients with negative dobutamine stress

Thomas F. Walsh; Erica Dall'Armellina; Haroon Chughtai; Timothy M. Morgan; William O. Ntim; Kerry M. Link; Craig A. Hamilton; Dalane W. Kitzman; W. Gregory Hundley

BackgroundTo determine if patients without dobutamine induced left ventricular wall motion abnormalities (WMA) but an increased LV end-diastolic wall thickness (EDWT) exhibit a favorable cardiac prognosis.ResultsBetween 1999 and 2001, 175 patients underwent a dobutamine stress cardiovascular magnetic resonance (DCMR) procedure utilizing gradient-echo cines. Participants had a LV ejection fraction >55% without evidence of an inducible WMA during peak dobutamine/atropine stress. After an average of 5.5 years, all participants were contacted and medical records were reviewed to determine the post-DCMR occurrence of cardiac death, myocardial infarction (MI), and unstable angina (USA) or congestive heart failure (CHF) warranting hospitalization.In a multivariate analysis, that took into account Framingham and other risk factors associated with cardiac events, a cine gradient-echo derived LV EDWT ≥12 mm was associated independently with an increase in cardiac death and MI (HR 6.0, p = 0.0016), and the combined end point of MI, cardiac death, and USA or CHF warranting hospitalization (HR 3.0, p = 0.0005).ConclusionSimilar to echocardiography, CMR measures of increased LV wall thickness should be considered a risk factor for cardiac events in individuals receiving negative reports of inducible ischemia after dobutamine stress. Additional prognostic studies of the importance of LV wall thickness and mass measured with steady-state free precession techniques are warranted.


European Journal of Haematology | 2013

Prolongation of QTc intervals and risk of death among patients with sickle cell disease

Bharathi Upadhya; William O. Ntim; Richard Brandon Stacey; Rick Henderson; David Leedy; Francis X. O'Brien; Mary Ann Knovich

Unexplained sudden death is common among patients with sickle cell diseases (SCD). QTc prolongation is a risk factor for fatal arrhythmias among adults. This study sought to identify the predictors for QTc prolongation and determine whether QTc prolongation is associated with increased mortality in patients with SCD.


Acta Haematologica | 2014

Echocardiography-Derived Tricuspid Regurgitant Jet Velocity Is an Important Marker for the Progression of Sickle-Cell Disease

Bharathi Upadhya; Richard Brandon Stacey; William O. Ntim; Mary Ann Knovich; Min Pu

Background: Although echocardiography-derived tricuspid regurgitant jet velocity (TRV) is associated with increased mortality in sickle-cell disease (SCD), it is unclear whether increased TRV is a marker of multiorgan disease due to systemic vasculopathy or related to increased pulmonary artery systolic pressure with episodes of multiple acute chest syndrome (ACS). Methods: Our study analyzed 148 consecutive patients with transthoracic echocardiography with TRV data, who came to our adult SCD Clinic at the Wake Forest Baptist Medical Center. For our analysis, we took TRV ≥2.5 m/s as elevated. Patients were followed on average for 9 years. Results: TRV ≥3 m/s was significantly associated with increased mortality (p < 0.001), thromboembolism (p < 0.001), hospitalization for ACS (p < 0.001), supraventricular arrhythmia (p = 0.028), right ventricular (RV) dilation, decreased hemoglobin and increased creatinine. Patients with a progressive increase in TRV during follow-up had increased mortality (36.7 vs. 8.6%, p = 0.007) and increased ACS (45 vs. 5.7%, p < 0.001). Death was independently associated with TRV ≥3 m/s (p = 0.023), ACS (p = 0.001) and increased RV basal diameter (p = 0.003). Conclusions: TRV is an important global marker for the severity and progression of SCD, and carries a significant prognostic implication.


Journal of the American College of Cardiology | 2010

Imaging surveillance for cardiovascular complications of cancer therapy.

William O. Ntim; W. Gregory Hundley

We read with great interest the state-of-the-art paper by Yeh and Bickford ([1][1]) on the cardiovascular complications of cancer therapy. Although the review on monitoring for chemotherapy associated left ventricular (LV) dysfunction discussed the role of established noninvasive tools, such as


Journal of Cardiovascular Computed Tomography | 2007

Endocarditis with perforation of a bicuspid aortic valve as shown by cardiac-gated multidetector computed tomography

Daniel W. Entrikin; William O. Ntim; Neal D. Kon; J. Jeffrey Carr

A previously healthy 35-year-old man sought treatment or fatigue, malaise, and persistent low-grade fevers. Blood ultures obtained were positive for Streptococcus viridans. eports from transthoracic (TTE) and transesophageal chocardiography (TEE) performed at an outside institution howed a bicuspid aortic valve with 1-cm vegetations on ne of the valve cusps and severe aortic insufficiency. He as referred to our institution for aortic valve replacement, nd a cardiac-gated computed tomography angiography CTA) was performed to assess for coronary artery disease.

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