Malik A. Al-Omari
Mayo Clinic
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Malik A. Al-Omari.
American Journal of Cardiology | 2008
Malik A. Al-Omari; Joshua Finstuen; Christopher P. Appleton; Marion E. Barnes; Teresa S.M. Tsang
Diastolic dysfunction has been linked to 2 epidemics: atrial fibrillation (AF) and heart failure. The presence and severity of diastolic dysfunction are associated with an increased risk for first AF and first heart failure in patients with sinus rhythm. Furthermore, the risk for heart failure is markedly increased once AF develops. The evaluation of diastolic function once AF has developed remains a clinical challenge. The conventional use of Doppler echocardiography for the assessment and grading of diastolic dysfunction relies heavily on evaluating the relation of ventricular and atrial flow characteristics. The mechanical impairment of the left atrium and the variable cycle lengths in AF render the evaluation of diastolic function difficult. A few Doppler echocardiographic methods have been proved clinically useful for the estimation of diastolic left ventricular filling pressures in AF, but these appear to be underutilized. Several innovative methods are emerging that promise to provide greater precision in diastolic function assessment, but their clinical utility in AF remains to be established. In conclusion, this review provides an up-to-date discussion of the evaluation of diastolic function assessment in AF and how it may be important in the clinical management of patients with AF.
Hypertension | 2011
Thais Coutinho; Malik A. Al-Omari; Thomas H. Mosley; Iftikhar J. Kullo
Left ventricular (LV) hypertrophy, a marker for adverse cardiovascular events, is more common in blacks than in non-Hispanic whites. Mechanisms leading to LV hypertrophy and mediating its clinical sequelae in blacks are not fully understood. We investigated the associations of 39 candidate biomarkers in distinct biological pathways with LV mass and geometry in blacks. Participants included 1193 blacks (63±9 years of age; 72% women; 78% hypertensive) belonging to hypertensive sibships. LV mass was measured by transthoracic echocardiography and indexed to height.2.7 LV geometry was categorized as normal, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy. Generalized estimating equations were used to assess associations of the 39 biomarkers with LV mass index after adjustment for age, sex, and conventional risk factors. After adjustment for potential confounders, log-transformed levels of the following biomarkers were independently associated with LV mass index: N-terminal pro-brain natriuretic peptide (&bgr;±SE=0.07±0.01 pg/mL; P<0.0001), mid-regional pro-atrial natriuretic peptide (&bgr;±SE=0.08±0.02 pmol/L; P<0.0001), mid-regional pro-adrenomedullin (&bgr;±SE=0.09±0.03 nmol/L; P=0.0006), C-terminal pro-endothelin (&bgr;± SE=0.05±0.02 pmol/L; P=0.0009), and osteoprotegerin (&bgr;±SE=0.07±0.02 pg/mL; P=0.0005) (&bgr; is for 1 log increase in biomarker level). The associations of these biomarkers with LV mass index were mainly due to their association with eccentric hypertrophy. Higher circulating levels of natriuretic peptides, adrenomedullin, endothelin, and osteoprotegerin were associated with increased LV mass index, providing insights into the pathophysiology of LV hypertrophy in blacks.
American Journal of Hypertension | 2009
Malik A. Al-Omari; Mahyar Khaleghi; Thomas H. Mosley; Stephen T. Turner; Nils G. Morgenthaler; Joachim Struck; Andreas Bergmann; Iftikhar J. Kullo
BACKGROUND African Americans with hypertension are prone to target-organ damage and adverse cardiovascular events. Biomarkers for early detection of target-organ damage in this ethnic group are needed. Adrenomedullin (ADM) is a circulating vasoactive peptide with vasodilatory and antiproliferative effects that has been reported to be elevated in adults with hypertension. METHODS We investigated the associations of plasma levels of mid-regional pro-ADM (MR-proADM) with pulse pressure, left ventricular mass (LVM), and albuminuria in 1,034 African-American adults (65 +/- 9 years, 72% women) with hypertension. MR-proADM was measured by an immunoluminometric assay, LVM was assessed by 2-dimensional echocardiography, and albuminuria was assessed by urine albumin:creatinine ratio (UACR). Multivariable regression analyses were used to assess whether plasma MR-proADM was independently associated with pulse pressure, LVM indexed by height to the power 2.7 (LVMi), and UACR. RESULTS Plasma MR-proADM was significantly correlated (P < 0.001) with pulse pressure, LVMi, and UACR. In separate multivariable linear regression models that adjusted for age and sex, log MR-proADM was associated with greater pulse pressure (P = 0.007), log LVMi (P = 0.001), and log (UACR+1) (P < 0.0001). After additional adjustment for body mass index (BMI), total and high-density lipoprotein (HDL) cholesterol, smoking history, diabetes, estimated glomerular filtration rate (eGFR), history of myocardial infarction (MI) or stroke, and medication use, log MR-proADM remained significantly associated with greater pulse pressure (P = 0.001), log LVMi (P = 0.029), and log (UACR+1) (P = 0.002). CONCLUSIONS In African-American adults with hypertension, plasma MR-proADM is independently associated with pulse pressure, LVMi, and albuminuria and is a potential biomarker for target organ damage.
American Journal of Cardiology | 2009
Mahyar Khaleghi; Malik A. Al-Omari; Venkateswarlu Kondragunta; Nils G. Morgenthaler; Joachim Struck; Andreas Bergmann; Thomas H. Mosley; Iftikhar J. Kullo
We tested the hypothesis that, in adults with essential hypertension, plasma levels of midregional proatrial natriuretic peptide (MR-proANP) are associated with target organ damage. MR-proANP is a newly described stable fragment of N-terminal proatrial natriuretic peptide. Participants included 1,919 adults with hypertension identified from the community (1,037 African-Americans, 65 +/- 9 years of age, 72% women; 882 non-Hispanic whites, 61 +/- 9 years of age, 55% women). We measured MR-proANP by an immunoluminometric assay. Measurements of target organ damage included the ankle-brachial index (ABI), urinary albumin-creatinine ratio (UACR), and left ventricular (LV) mass (available only in African-Americans). Generalized estimating equations were used to assess whether plasma MR-proANP was associated with measurements of target organ damage, independent of potential confounding variables. In African-Americans, higher MR-proANP was significantly associated with lower ABI (p <0.0001), higher UACR (p <0.0001), and greater LV mass (indexed to height to the power of 2.7, p <0.0001). After adjustment for age, gender, body mass index, systolic blood pressure, estimated glomerular filtration rate, smoking history, diabetes mellitus, total and high-density lipoprotein cholesterols, medication (blood pressure lowering, statin, and aspirin) use, and previous myocardial infarction or stroke, higher MR-proANP levels remained significantly associated with lower ABI (p = 0.01), higher UACR (p = 0.0007), and greater LV mass index (p <0.0001). In non-Hispanic whites, higher MR-proANP levels were significantly associated with lower ABI (p = 0.002) and greater UACR (p = 0.001), but not after adjustment for the covariates listed earlier. In conclusion, plasma MR-proANP may be a marker of target organ damage in the setting of hypertension, especially in African-Americans.
Journal of Heart and Lung Transplantation | 2011
Eugenia Raichlin; Malik A. Al-Omari; Courtney L. Hayes; Brooks S. Edwards; Robert P. Frantz; Barry A. Boilson; Alfredo L. Clavell; Richard J. Rodeheffer; John A. Schirger; Sudhir S. Kushwaha; Thomas G. Allison; Naveen L. Pereira
BACKGROUND Exercise performance, an important aspect of quality of life, remains limited after heart transplantation (HTx). This study examines the effect of cardiac allograft remodeling on functional capacity after HTx. METHODS The total cohort of 117 HTx recipients, based on echocardiographic determination of left ventricle mass and relative wall thickness at 1 year after HTx, was divided into 3 groups: (1) NG, normal geometry; (2) CR, concentric remodeling; and (3) CH, concentric hypertrophy. Cardiopulmonary exercise testing was performed 5.03 ± 3.08 years after HTx in all patients. Patients with acute rejection or significant graft vasculopathy were excluded. RESULTS At 1 year post-HTx, 30% of patients had CH, 55% had CR and 15% had NG. Exercise tolerance, measured by maximum achieved metabolic equivalents (4.62 ± 1.44 vs 5.52 ± 0.96 kcal/kg/h), normalized peak Vo(2) (52 ± 14% vs 63 ± 12%) and Ve/Vco(2) (41 ± 17 vs 34 ± 6), was impaired in the CH group compared with the NG group. A peak Vo(2) ≤14 ml/kg/min was found in 6%, 22% and 48% of patients in the NG, CR and CH groups, respectively (p = 0.01). The CH pattern was associated with a 7.4-fold increase in relative risk for a peak Vo(2) ≤14 ml/kg/min compared with NG patients (95% confidence interval 1.1 to 51.9, p = 0.001). After multivariate analysis, a 1-year CH pattern was independently associated with a reduced normalized peak Vo(2) (p = 0.018) and an elevated Ve/Vco(2) (p = 0.035). CONCLUSIONS The presence of CH at 1 year after HTx is independently associated with decreased normalized peak Vo(2) and increased ventilatory response in stable heart transplant recipients. The identification of CH, a potentially reversible mechanism of impairment in exercise capacity after HTx, may have major clinical implications.
Journal of Human Hypertension | 2011
Malik A. Al-Omari; Mahyar Khaleghi; Thomas H. Mosley; Nils G. Morgenthaler; Joachim Struck; Andreas Bergmann; Iftikhar J. Kullo
Endothelin-1 (ET-1), a circulating vasoactive peptide with potent vasoconstricting and mitogenic properties, may contribute to target-organ damage in hypertension. We investigated whether plasma levels of C-terminal pro-endothelin-1 (CT-pro-ET-1) are associated with left ventricular (LV) mass and aortic root diameter in African-American adults with hypertension. Plasma CT-pro-ET-1 was measured by an immunoluminometric assay in 1041 African Americans (65±9 years, 72% women) with hypertension. LV mass and aortic root diameter were measured according to the American Society of Echocardiography guidelines, and LV mass was indexed by height to the power 2.7 (LVMi). Multivariable regression analyses were used to assess whether plasma CT-pro-ET-1 was associated with LVMi and aortic root diameter, independent of potential confounding variables. Plasma CT-pro-ET-1 was modestly correlated with LVMi (r=0.21, P<0.0001) and aortic root diameter (r=0.09, P=0.004). In separate multivariable regression models that adjusted for age, sex, body mass index, total and high-density lipoprotein cholesterol, smoking history, diabetes, history of myocardial infarction or stroke, and blood pressure-lowering medication and statin use, log CT-pro-ET-1 was significantly associated with greater LVMi (P=0.001) and larger aortic root diameter (P=0.006). CT-pro-ET-1 is independently associated with LVMi and aortic root diameter and may be a marker of target-organ damage in African-Americans adults with hypertension.
American Journal of Hypertension | 2010
Ammar Habib; Malik A. Al-Omari; Mahyar Khaleghi; Nils G. Morgenthaler; Joachim Struck; Andreas Bergmann; Thomas H. Mosley; Stephen T. Turner; Iftikhar J. Kullo
BACKGROUND Endothelin-1 (ET-1) is a vasoactive peptide with vasoconstrictor and mitogenic properties. We investigated whether plasma levels of C-terminal pro-ET-1 (CT-proET-1), a newly described stable fragment of the ET-1 precursor, are associated with target-organ damage in hypertension. METHODS Participants included 981 African Americans (65 ± 9 years, 71% women) and 812 non-Hispanic whites (61 ± 9 years, 54% women) ascertained from sibships with hypertension. We measured plasma CT-proET-1 by an immunoluminometric assay. Measures of target-organ damage included the ankle-brachial index (ABI) and urinary albumin:creatinine ratio (UACR). Multivariable regressions analyses were employed to assess whether plasma CT-proET-1 levels were independently associated with ABI and UACR. RESULTS In hypertensive African Americans, higher plasma levels of CT-proET-1 were significantly associated with lower ABI (P < 0.01) and higher UACR (P < 0.01). After adjustment for age, sex, body mass index, systolic blood pressure (SBP) and diastolic blood pressure (BP), diabetes, serum glucose, insulin use, estimated glomerular filtration rate (eGFR), history of smoking, total and high-density lipoprotein cholesterol, medication use, and previous history of myocardial infarction (MI) or stroke, higher plasma levels of CT-proET-1 remained significantly associated with lower ABI (P < 0.01) and higher UACR (P = 0.02). In non-Hispanic white hypertensives, higher plasma levels of CT-proET-1 were weakly associated with higher UACR (P = 0.02) and with lower ABI (P = 0.07). After adjustment for the relevant covariates, no statistically significant associations between CT-proET-1 and ABI or UACR were present in whites. CONCLUSIONS Plasma levels of CT-proET-1 were independently associated with lower ABI and greater UACR in African American but not non-Hispanic white adults with hypertension.
Heart | 2012
Joseph L. Blackshear; Robert E. Safford; Paul Fredrickson; Colleen S. Thomas; Michael G. Heckman; Malik A. Al-Omari; Joseph Kaplan
To the Editor: Three unblinded studies of night-time oxygen in patients with Cheyne Stokes Respirations and congestive heart failure (CSR-CHF) showing subjective improvements in exercise capacity, and New York Heart Association Classification versus parallel controls, and an increase in left ventricular ejection fraction of between 5% and 10%,1–3 were undertaken. On the basis of these studies, it was found that home oxygen therapy is in widespread use and is covered by national insurance in Japan, but is not sanctioned by international CHF guidelines. Respiratory-based therapies are subject to placebo effect, and oxygen is no exception.4 Amid concern regarding the inadequacy of the scientific basis for the prescription of night-time oxygen therapy, two additional trials in the UK (ISRCTN60260702) and Australia (ACTRN12609000103268) are in early enrolment. In discussing these ongoing studies, a tepid recommendation for the use of night-time oxygen was stated. …
Catheterization and Cardiovascular Interventions | 2013
Malik A. Al-Omari; Michael S. Levy
Surgical replacement has been established as the gold standard treatment for severe aortic stenosis and continues to offer symptomatic relief and survival benefit in those patients felt to be appropriate candidates [1]. Despite the improved perioperative mortality attributed to the improvement in surgical technique, circulatory support, and anesthesia, many patients with severe symptomatic aortic stenosis are declined surgery because of comorbidities, advanced age, or previous sternotomy. Moreover, a significant percentage of patients without severe comorbidities are not referred for surgical evaluation [2]. Transcatheter aortic valve replacement (TAVR) has emerged as an alternative to surgical aortic valve replacement in elderly and in high-risk inoperable patients with severe aortic stenosis. The rise in TAVR use worldwide and improvements in this technology has contributed to an increase in the expertise of operators and centers involved in this procedure. Balloon aortic valvuloplasty (BAV) is currently considered part of standard operating procedure prior to device deployment in TAVR regardless of device used. However, experience has shown that BAV is associated with various complications including atrioventricular block, aortic valve regurgitation, and calcium debris embolization. Additionally, rapid pacing, which is often used in BAV, causes hypotension, which may not be well tolerated in elderly patients and those with low ejection fraction. Moreover, rapid ventricular pacing in patients with atrial fibrillation may increase stroke risk. While performing BAV prior to device deployment should, in theory, make crossing the severely calcified valve easier and may provide better device deployment with less paravalvular regurgitation, it is unclear whether BAV prior to device deployment is needed in all patients undergoing TAVR. In this issue of Catheterization & Cardiovascular Interventions, Mendiz et al. [3] report a single center experience of performing transcatheter CoreValve (Medtronic, Minneapolis, MN) prosthesis implantation without predilatation BAV. This study serves as a follow-up to a previously published pilot study of 60 multicenter patients receiving direct implantation of a Corevalve device without predilatation [4]. The current study included 51 high surgical risk consecutive patients who underwent TAVR mainly through the transfemoral approach. The mean age of patients was 79 6 8 years, 74% were New York Heart Association classes III or IV, and the mean logistic Euroscore of the group was 20 6 15. The procedure was successfully completed in 94.2% of patients. However, balloon post dilation was needed in 16 (31.3%) of the cases to expand the valve and decrease aortic valve regurgitation. Although this is a small case series, it is progressive in its attempt to modify and simplify the TAVR procedure as a whole. Certainly, in this population of patients who underwent Corevalve implantation, the idea of no upfront BAV or pacing prior to deployment of the device is very attractive. In comparision with other historical trials the complication rate in this trial is within acceptable range and may potentially be lower than described by other trials. What remains to be seen is how reproducible this method will be on a larger scale and what the overall outcomes will be. Additionally, it will be interesting to see if this approach will be possible for future devices that are both self-expanding or balloon expandable. Given the study population described, one could hypothesize that aortic calcium should be a predictor of need for postdilatation BAV. However, severe aortic valve calcification was reported in 30 (63%) of cases, which raises the possibility that this is not the sole predictor of need for postdilatation. Further study will be
Heart | 2010
Malik A. Al-Omari; Eugenia Raichlin; Brooks S. Edwards; Richard J. Rodeheffer; Robert P. Frantz; Naveen L. Pereira; Alfredo L. Clavell; Sudhir S. Kushwaha
Purpose Although transition to sirolimus (SRL) as primary immunosuppression has been associated with an improvement in glomerular filtration rate (GFR), long term follow up has not been reported. The aim of this study was to evaluate GFR in SRL treated patients and to compare with patients remained on CNIs during 5 years follow-up (FU). Methods and Materials The study population consisted of 85 cardiac transplant recipients with impaired renal function and/or cardiac allograft vasculopathy in whom CNIs were substituted with sirolimus (SRL group) and 86 cardiac transplant recipients maintained on CNI based immunosuppression (CNI group). Secondary immunosuppressants were not changed. GFR was measured by corrected iothalamate clearance. Results Mean follow up was 5.3 (IQR 3.7, 6.1) years. GFR increased from 53.522.4 to 59.524.7 mL/min (p=0.03) 4 years after SRL initiation while in the CNI group, GFR declined from 57.021.8 to 53.120.6 mL/min (p=0.03) in the same period of FU. In multivariate logistic regression analysis, treatment with CNI (p=0.04), lower GFR at study entry (p=0.03), and ischaemic aetiology of cardiomyopathy prior to transplantation (p=0.04), were all associated with long term worsening of GFR. In the SRL group, improvement in GFR was significant in patients with GFR 40 mL/min prior to conversion but not in patients with GFR<40 mL/min. At the end of FU, 3 (4%) vs 6 (7%) (p=0.018), 3 (4%) vs 11 (13%) (p=0.33), and 7 (8%) vs 23 (28%) (p=0.001), in the SRL group vs the CNI group had kidney transplant, required haemodialysis, and died respectively. Conclusions Substitution of CNIs with SRL in stable cardiac transplant recipients was associated with improved renal function, particularly in patients with GFR 40 mL/min prior to conversion, and survival. These results suggest that the initial improvement seen with substituting SRL for CNIs is sustained over a longer FU period and this strategy has the potential to improve long-term outcome in cardiac transplantation.