Tarek A N Ahmed

Leiden University Medical Centre, Leiden, South Holland, Netherlands

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Publications (9)40.88 Total impact

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    International journal of cardiology 01/2014; · 6.18 Impact Factor
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    ABSTRACT: The clinical use of advanced imaging modalities for early determination of infarct size and prognosis is limited. As a specific indicator of myocardial necrosis, cardiac troponin T (cTnT) can be used as a surrogate measure for this purpose. The present study sought to investigate the use of peak and serial 6-hour fixed-time high-sensitive (hs) cTnT for estimation of infarct size, left ventricular (LV) function, and prognosis in consecutive patients with ST-segment elevation myocardial infarction. The infarct size was expressed as the 48-hour cumulative creatine kinase release. LV function at 3 months was assessed using the echocardiographic wall motion score index and LV ejection fraction using radionuclide ventriculography. Adverse outcomes, comprising all-cause death, implantable cardioverter-defibrillator implantation, or hospitalization for heart failure, were recorded at 1 year of follow-up. In 188 patients, the peak and all fixed-time values correlated significantly with the 48-hour cumulative creatine kinase release, wall motion score index, and LV ejection fraction. The hs-cTnT value at 24 hours demonstrated the greatest correlation (r = 0.86, r = 0.47, and r = -0.59, respectively; p <0.001 for all). In the multivariate regression models adjusted for the clinical parameters, almost all were independently associated with the 48-hour cumulative creatine kinase release, wall motion score index, and LV ejection fraction, with the hs-cTnT value at 24 hours having the largest effect. Moreover, all cTnT values independently predicted adverse outcomes, again, with the hs-cTnT value at 24 hours showing the largest influence (hazard ratio 3.77, 95% confidence interval 2.12 to 6.73, p <0.001). In conclusion, not only peak, but all fixed-time hs-cTnT values were associated with infarct size, LV function at 3 months, and adverse outcomes 1 year after ST-segment elevation myocardial infarction. The value 24 hours after the onset of symptoms had the closest associations with all outcomes. Therefore, serial sampling for a peak value might be redundant.
    The American journal of cardiology 02/2013; · 3.58 Impact Factor
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    ABSTRACT: In patients with ST-elevation myocardial infarction (STEMI), high thrombotic burden, subsequent distal embolisation and myocardial no-reflow remain a large obstacle that may negate the benefits of urgent coronary revascularisation. We aimed at assessing the predictors of: 1) thrombus grade in patients undergoing primary percutaneous coronary intervention (PPCI) and 2) infarct size, in order to optimise therapy to reduce thrombus burden. One-hundred and fifty-three consecutive patients presenting with STEMI and undergoing PPCI were included. Thrombus was evaluated by angiography and scored according to the TIMI study group score. Next, patients were categorised into two groups that had either high thrombus grade (HTG; score 4-5) or low thrombus grade (LTG; score 1-3). We evaluated predictors of angiographic thrombus grade among a number of clinical, angiographic and laboratory data. We also assessed infarct size and scintigraphic left ventricular ejection fraction (LVEF) at three months in both patient groups. Ninety-four patients (58±11 years; 75% males) presented with HTG, whereas 59 patients (58±12 years; 78% males) presented with LTG. Pre-infarction angina (PIA) was more frequently encountered in the LTG group than in the HTG group (25% vs. 10%, p=0.009). Pre-procedural TIMI flow was significantly lower in the HTG group (p<0.001), and thrombosuction was more frequently applied in the HTG group (p<0.001). Absence of PIA (OR=0.29, 95% CI=0.11-0.75, p=0.01) and proximal culprit lesion (OR=2.10, 95% CI=1.02-4.36, p=0.04) were the only independent predictors of HTG. HTG proved an independent predictor of higher peak levels of creatine kinase (CK) (p<0.001) and troponin T (p<0.001), as well as lower LVEF (p=0.05) along with male gender and absence of prior statin therapy. Absence of PIA and proximal culprit lesions are associated with higher thrombus grade. Higher thrombus grade is associated with larger infarct size and slightly worse LV function. This may have clinical implications in planning strategies, particularly regarding pharmacotherapy, that aim to decrease thrombus burden prior to stent implantation.
    EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology 04/2012; 7(12):1396-405. · 3.17 Impact Factor
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    ABSTRACT: The techniques and materials used during percutaneous coronary intervention have advanced considerably over the past 3 decades, yet restenosis remains one of the major drawbacks of this procedure. Many innovative technologies, including drug-eluting stents, with or without specific polymers, and fully biodegradable stents have been and continue to be developed in the search for a safe and effective antirestenosis therapy. Remarkable advances in stent design and nanoparticle delivery systems ('nanovehicles') have already fueled revolutionary changes in the prevention and treatment of in-stent restenosis. In this Review we provide an overview of the latest innovations for optimizing outcomes of coronary stenting, and up-to-date information about prevention and treatment of in-stent restenosis.
    Nature Reviews Cardiology 02/2012; 9(2):79-90. · 10.40 Impact Factor
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    ABSTRACT: The benefits of early abciximab administration and thrombus aspiration in ST elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI) have previously been elaborated. However, whether there is an adjunctive effect of thrombus aspiration among STEMI patients, with angiographic evidence of thrombus, receiving early prehospital abciximab remains unclear.  In the context of a fixed protocol for PPCI, 158 consecutive patients with STEMI were enrolled, in whom abciximab was started early before hospital arrival (in-ambulance); 79 patients who had PPCI with thrombus aspiration (thrombectomy-facilitated PCI group), were compared to 79 who had PPCI without thrombus aspiration (conventional PCI group) in a prospective nonrandomized study. The primary end-point was complete ST-segment resolution within 90 minutes. Secondary end points included distal embolization, enzymatic infarct size as well as left ventricular ejection fraction (LVEF) assessed by gated single-photon emission computed tomography. Major adverse cardiac events (MACEs) were evaluated up to 12 months.  Both groups were comparable for baseline characteristics. ST-segment resolution was significantly higher in the thrombectomy-facilitated group (P = 0.002), and multivariate analysis identified thrombectomy as an independent predictor of ST-segment resolution (OR = 9.4, 95% CI = 2.6-33.5, P = 0.001). Distal embolization was higher in the conventional PCI group among patients with higher thrombus grades. No difference was observed between both groups in infarct size assessed by peak creatine kinase (p = 0.689) and peak Tn-T levels (P = 0.435). Also, the LVEF at 3 months was similar (P = 0.957). At 12 month clinical follow-up, thrombus aspiration was, however, associated with reduced all-cause mortality (log-rank p = 0.032).  Among STEMI patients treated with PPCI and in-ambulance abciximab, it appears that a selective strategy of thrombus aspiration still has additive benefit.
    Journal of Interventional Cardiology 11/2011; 25(1):1-9. · 1.50 Impact Factor
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    ABSTRACT: Restenosis is a complex disease for which the pathophysiological mechanisms have not yet been fully elucidated, but are thought to include inflammation, proliferation, and matrix remodeling. Over the years, many predictive clinical, biological, (epi)genetic, lesion-related, and procedural risk factors for restenosis have been identified. These factors are not only useful in risk stratification of patients, they also contribute to our understanding of this condition. Furthermore, these factors provide evidence on which to base treatment tailored to the individual and aid in the development of novel therapeutic modalities. In this Review, we will evaluate the available evidence on the pathophysiological mechanisms of restenosis and provide an overview of the various risk factors, together with the possible clinical application of this knowledge.
    Nature Reviews Cardiology 09/2011; 9(1):53-62. · 10.40 Impact Factor
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    ABSTRACT: Different biodegradable-polymer drug-eluting stents have not yet been systematically analysed. We sought to; 1) evaluate the risk of target lesion revascularisation (TLR) and definite stent thrombosis (DST) among different groups of biodegradable-polymer (BioPol) DES, and 2) to compare them with permanent polymer (PermPol) DES. We searched PubMed and relevant sources from January 2005 until October 2010. Inclusion criteria were (a) Implantation of a drug-eluting stent with biodegradable polymer; (b) available follow-up data for at least one of the clinical end-points (TLR/DST) at short term (30 days) and/or mid-term (one year). A total of 22 studies, including randomised and observational studies, with 8264 patients met the selection criteria; nine studies (2042 patients) in whom biodegradable-polymer sirolimus eluting stents (BioPol-SES) were implanted, eight studies (1731 patients) in whom biodegradable-polymer paclitaxel eluting stents (BioPol-PES) were implanted, and seven studies (4491 patients) in whom biodegradable-polymer biolimus-A9 eluting stents (BioPol-BES) were implanted. At 30 days, there was a higher risk of DST (p=0.04) and subsequently TLR (p=0.006) in the BioPol-BES compared to BioPol-SES, with no significant difference in the other stent comparisons. At 1-year, there was higher risk of TLR in the BioPol-PES (p=0.01), and the BioPol-SES (p=0.04) compared to BioPol-BES. One-year stent thrombosis was not statistically different between the studied groups (overall p=0.2). In another analysis comprising seven randomised trials comparing BioPol-DES (3778 patients) and PermPol-DES (3291 patients), the risks of TLR and stent thrombosis at 1-year were not significantly different (p=0.5 for both). Performance of different BioPol-DES seems to vary from each other. The short- and mid-term success rates may not be superimposable. Furthermore, they may not be necessarily better than PermPol-DES.
    EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology 08/2011; 7(4):505-16. · 3.17 Impact Factor
  • Tarek A N Ahmed, Ioannis Karalis, J Wouter Jukema
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    ABSTRACT: INTRODUCTION: Coronary artery disease (CAD) is one of the major causes of morbidity and mortality worldwide, exerting a huge economic burden. Although drug treatment in the past decades has made large advances, significant residual risk remains. However, in the coming years, there are still a lot of great advances and major breakthroughs expected. AREAS COVERED: New treatments are expected to provide higher efficacy with favorable safety profiles. In this review article, we provide an almost complete overview of the recent and emerging drug therapies of CAD. This includes: drugs for the treatment of atherogenic dyslipidemia, drugs that stabilize atherosclerotic plaques and halt their progression guided by novel anti-inflammatory concepts in atherosclerosis treatment, anti-anginal treatments, renin-angiotensin-aldosterone system inhibitors, antiplatelet and anticoagulant drugs. EXPERT OPINION: Efforts have been made to improve the clinical effectiveness and safety of established treatment strategies and target new frontiers through developing novel treatment strategies that tackle different mechanisms of action. Better understanding of the different molecular and cellular mechanisms underlying CAD has resulted in more innovations and achievements in CAD drug therapy, and still a lot more is anticipated in the coming years.
    Expert Opinion on Emerging Drugs 01/2011; 16(2):203-33. · 2.48 Impact Factor
  • Journal of The American College of Cardiology - J AMER COLL CARDIOL. 01/2011; 57(14).