Browsing by Author "Khan, Abdur Rahman"

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    Conflicts of Interest and Outcomes of Cardiovascular Trials.
    (Am J Cardiol, 2016-03-01) Riaz, Haris; Khan, Muhammad Shahzeb; Riaz, Irbaz Bin; Raza, Sajjad; Khan, Abdur Rahman; Krasuski, Richard A
    Conflicts of interests have long been recognized as potential sources of influence in the conduct and reporting of clinical trials. This controversy was again rekindled after the publication of the latest statin guidelines and a series of studies regarding competing interests in leading medical journals. We investigate the association between declared author conflicts and the outcomes of large cardiovascular trials. We searched the Medline (PubMed) database to identify "phase 2" and "phase 3" clinical trials using the search term "cardiovascular" over the past decade using "10 years" as the filter. We perceived the competing interest as present regardless of the nature such as consulting fees, honoraria, travel imbursements, stock holding, and employment. Of the 699 titles retrieved, 114 studies met the inclusion criteria. Nearly 80% of studies had at least a single author with competing interests. The 114 studies had a total of 1,433 investigators, of which 725 had declared conflicts of interests (50.6%). A total of 66 studies (58%) had half or >50 percent of investigators who had some conflicts of interests. Of these studies, 54 studies had favorable outcomes and only 12 had unfavorable outcomes (p <0.001). Among the type of competing interests, consulting or personal fees was the most common present in 58 investigators (51%). This was followed by research grants present in 55 the researchers (48%). Among 25 (22%) studies, at least one investigator reported stakes in the industry, of which only 2 studies had unfavorable outcomes for the intervention being investigated. Just 1 of the 25 clinical trials with a sample size of >1,000 had no investigators with competing interests. In conclusion, authors conflicts are associated with favorable outcomes in cardiovascular outcome trials.
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    Meta-analysis of Placebo-Controlled Randomized Controlled Trials on the Prevalence of Statin Intolerance.
    (Am J Cardiol, 2017-09-01) Riaz, Haris; Khan, Abdur Rahman; Khan, Muhammad Shahzeb; Rehman, Karim Abdur; Alansari, Shehab Ahmad Redha; Gheyath, Bashaer; Raza, Sajjad; Barakat, Amr; Luni, Faraz Khan; Ahmed, Haitham; Krasuski, Richard A
    The prevalence of intolerance varies widely. Stopping statin therapy is associated with worse outcomes in patients with cardiovascular disease. Despite extensive studies, the benefits and risks of statins continue to be debated by clinicians and the lay public. We searched the PubMed, Medline, and Cochrane Central Register of Controlled Trials (CENTRAL) databases for all randomized controlled trials of statins compared with placebo. Studies were included if they had ≥1,000 participants, had patients who were followed up for ≥1 year, and reported rates of drug discontinuation. Studies were pooled as per the random effects model. A total of 22 studies (statins = 66,024, placebo = 63,656) met the inclusion criteria. The pooled analysis showed that, over a mean follow-up of 4.1 years, the rates of discontinuation were 13.3% (8,872 patients) for statin-treated patients and 13.9% (8,898 patients) for placebo-treated patients. The random effects model showed no significant difference between the placebo and statin arms (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.93 to 1.06). The results were similar for both primary prevention (OR = 0.98, 95% CI = 0.92 to 1.05, p = 0.39) and secondary prevention (OR = 0.92, 95% CI = 0.83 to 1.05, p = 0.43) studies. The pooled analysis suggested that the rates of myopathy were also similar between the statins and placebos (OR = 1.2, 95% CI = 0.88 to 1.62, p = 0.25). In conclusion, this meta-analysis of >125,000 patients suggests that the rate of drug discontinuation and myopathy does not significantly differ between statin- and placebo-treated patients in randomized controlled trials. These findings are limited by the heterogeneity of results, the variable duration of follow-up, and the lower doses of statins compared with contemporary clinical practice.
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    Safety and Use of Anticoagulation After Aortic Valve Replacement With Bioprostheses: A Meta-Analysis.
    (Circ Cardiovasc Qual Outcomes, 2016-05) Riaz, Haris; Alansari, Shehab Ahmad Redha; Khan, Muhammad Shahzeb; Riaz, Talha; Raza, Sajjad; Luni, Faraz Khan; Khan, Abdur Rahman; Riaz, Irbaz Bin; Krasuski, Richard A
    BACKGROUND: The American College of Cardiology guidelines recommend 3 months of anticoagulation after replacement of the aortic valve with a bioprosthesis. However, there remains great variability in the current clinical practice and conflicting results from clinical studies. To assist clinical decision making, we pooled the existing evidence to assess whether anticoagulation in the setting of a new bioprosthesis was associated with improved outcomes or greater risk of bleeding. METHODS AND RESULTS: We searched the PubMed database from the inception of these databases until April 2015 to identify original studies (observational studies or clinical trials) that assessed anticoagulation with warfarin in comparison with either aspirin or no antiplatelet or anticoagulant therapy. We included the studies if their outcomes included thromboembolism or stroke/transient ischemic attacks and bleeding events. Quality assessment was performed in accordance with the Newland Ottawa Scale, and random effects analysis was used to pool the data from the available studies. I(2) testing was done to assess the heterogeneity of the included studies. After screening through 170 articles, a total of 13 studies (cases=6431; controls=18210) were included in the final analyses. The use of warfarin was associated with a significantly increased risk of overall bleeding (odds ratio, 1.96; 95% confidence interval, 1.25-3.08; P<0.0001) or bleeding risk at 3 months (odds ratio, 1.92; 95% confidence interval, 1.10-3.34; P<0.0001) compared with aspirin or placebo. With regard to composite primary outcome variables (risk of venous thromboembolism, stroke, or transient ischemic attack) at 3 months, no significant difference was seen with warfarin (odds ratio, 1.13; 95% confidence interval, 0.82-1.56; P=0.67). Moreover, anticoagulation was also not shown to improve outcomes at time interval >3 months (odds ratio, 1.12; 95% confidence interval, 0.80-1.58; P=0.79). CONCLUSIONS: Contrary to the current guidelines, a meta-analysis of previous studies suggests that anticoagulation in the setting of an aortic bioprosthesis significantly increases bleeding risk without a favorable effect on thromboembolic events. Larger, randomized controlled studies should be performed to further guide this clinical practice.