Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers and Mortality Among COVID-19 Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are known to increase the expression of angiotensin converting enzyme 2 receptor, which has been shown to be the receptor for the acute severe respiratory syndrome coronavirus 2 (SARS-CoV-2). AREAS OF UNCERTAINTY: Based on these observations, speculations raised the concerns that ACEIs/ARBs users would be more susceptible to SARS-CoV-2 infection and would be at higher risk for severe COVID-19 disease and death. Therefore, we systematically reviewed the literature and performed a meta-analysis of the association between prior use of ACEIs and ARBs and mortality due to COVID-19 disease. DATA SOURCES: A comprehensive search of several databases from November 2019 to June 18, 2020 was conducted. The databases included Ovid MEDLINE(R) and Epub Ahead of Print, In-Process and Other Non-Indexed Citations and Daily, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, Web of Science, and Scopus. Medrxiv.org was also searched for unpublished data. THERAPEUTIC ADVANCES: Nine studies with a total of 18,833 patients infected with SARS-CoV-2 met our eligibility criteria. Prior use of ACEIs and/or ARBs was associated with reduced mortality among SARS-CoV-2-infected patients, with a pooled adjusted relative risk (aRR) from 6 studies of 0.63, 95% confidence interval (CI) (0.42-0.94) (I 2 = 65%). Three studies reported separately on ACEIs or ARBs and their association with survival among SARS-CoV-2-infected patients, with a pooled adjusted relative risk of 0.78, 95% CI (0.58-1.04) (I 2 = 0%) and 0.97, 95% CI (0.73-1.30) (I 2 = 0%) respectively. The results of sensitivity analyses were consistent with the main analysis. CONCLUSION: Our meta-analysis suggests that use of ACEIs/ARBs is associated with a decreased risk of death among SARS-CoV-2-infected patients. This finding provides a reassurance to the public not to stop prescribed ACEIs/ARBs because of fear of severe COVID-19.

Molecular Epidemiology of Carbapenem-Resistant K. pneumoniae Clinical Isolates from the Adult Patients with Comorbidities in a Tertiary Hospital, Southern Saudi Arabia.

Hospitalized patients are likely to have chronic illnesses and are at an increased risk of mortality due to infection caused by MDR bacteria. We aimed to identify carbapenem-resistant genes carrying Klebsiella pneumoniae (K. pneumoniae) isolates and their risk factors recovered from adult patients with comorbidities. A cross-sectional study was carried out between April 2021 and December 2021 at King Abdullah Hospital (KAH) in Bisha province, Saudi Arabia. Seventy-one multi-drug resistant K. pneumoniae recovered from clinical samples and screened for carbapenemase genes of blaOXA-48-like, blaNDM-1, blaKPC, blaVIM, and blaIMP. Of 71 MDR K. pneumoniae examined, 47 (66.2%) isolates harbored various carbapenemase genes. The most prevalent single resistance gene was blaOXA-48-like (62.5%; n = 25), and 33.3% of them were recovered from sputum isolates. The blaNDM-1 gene was detected in 12 (30.0%) isolates, and eight of them were recovered from urine (n = 4) and blood (n = 4). Two (5.0%) single blaKPC genes were recovered from the sputum (n = 1) and blood (n = 1) isolates. In contrast, no blaIMP- and blaVIM-carrying isolates were detected. The co-existence of two resistance genes between blaOXA-48-like and blaNDM-1 was found in six strains, whereas only one strain was found to be produced in the three genes of blaNDM-1, blaKPC, and blaOXA-48-like. There were statistically significant associations between the presence of carbapenem-gene-carrying K. pneumoniae and patients' gender (χ2(1) = 5.94, p = 0.015), intensive care unit admission (χ2(1) = 7.649, p = 0.002), and chronic obstructive pulmonary disease (χ2(1) = 4.851, p = 0.028). The study highlighted the existence of carbapenemase-producing K. pneumoniae, particularly blaOXA-48-like and blaNDM-1, in patients with comorbidities. Our findings emphasize the importance of the molecular characterization of resistance-determinant-carrying bacterial pathogens as a part of infection control and prevention in hospital settings.

Cardiac Toxicity of Chloroquine or Hydroxychloroquine in Patients With COVID-19: A Systematic Review and Meta-regression Analysis.

OBJECTIVE: To systematically review the literature and to estimate the risk of chloroquine (CQ) and hydroxychloroquine (HCQ) cardiac toxicity in patients with coronavirus disease 2019 (COVID-19). METHODS: We searched multiple data sources including PubMed/MEDLINE, Ovid Embase, Ovid EBM Reviews, Scopus, and Web of Science and medrxiv.org from November 2019 through May 27, 2020. We included studies that enrolled patients with COVID-19 treated with CQ or HCQ, with or without azithromycin, and reported on cardiac toxic effects. We performed a meta-analysis using the arcsine transformation of the different incidences. RESULTS: A total of 19 studies with a total of 5652 patients were included. The pooled incidence of torsades de pointes arrhythmia, ventricular tachycardia, or cardiac arrest was 3 per 1000 (95% CI, 0-21; I 2 =96%) in 18 studies with 3725 patients. Among 13 studies of 4334 patients, the pooled incidence of discontinuation of CQ or HCQ due to prolonged QTc or arrhythmias was 5% (95% CI, 1-11; I 2 =98%). The pooled incidence of change in QTc from baseline of 60 milliseconds or more or QTc of 500 milliseconds or more was 9% (95% CI, 3-17; I 2 =97%). Mean or median age, coronary artery disease, hypertension, diabetes, concomitant QT-prolonging medications, intensive care unit admission, and severity of illness in the study populations explained between-studies heterogeneity. CONCLUSION: Treatment of patients with COVID-19 with CQ or HCQ is associated with an important risk of drug-induced QT prolongation and relatively higher incidence of torsades de pointes, ventricular tachycardia, or cardiac arrest. Therefore, these agents should not be used routinely in the management of COVID-19 disease. Patients with COVID-19 who are treated with antimalarials for other indications should be adequately monitored.

Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers and the Risk of SARS-CoV-2 Infection or Hospitalization With COVID-19 Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: SARS-CoV-2 infects its target cells via angiotensin converting enzyme 2 receptor, a membrane-bound protein found on the surface of many human cells. Treatment with angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptors blockers (ARB) has been shown to increase angiotensin converting enzyme 2 expression by up to 5-fold. AREAS OF UNCERTAINTY: These findings coupled with observations of the high prevalence and mortality among SARS-CoV-2-infected patients with underlying cardiovascular disease have led to a speculation that ACEIs/ARBs may predispose to higher risk of being infected with SARS-CoV-2. Therefore, we systematically reviewed the literature and performed a meta-analysis of the association between prior use of ACEIs and ARBs and the risk of SARS-CoV-2 infection or hospitalization due to COVID-19 disease. DATA SOURCES: We searched Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, Web of Science, Scopus, and Medrxiv.org preprint server until June 18, 2020. THERAPEUTIC ADVANCES: Ten studies (6 cohorts and 4 case control) that enrolled a total of 23,892 patients and 853,369 controls were eligible for inclusion in our meta-analysis. One study was excluded from the analysis because of high risk of bias. Prior use of ACEIs was not associated with an increased risk of acquiring SARS-CoV-2 or hospitalization due to COVID-19 disease, odds ratio 0.98, 95% confidence interval (0.91-1.05), I2 = 15%. Similarly, prior use of ARBs was not associated with an increased risk of acquiring SARS-CoV-2, odds ratio 1.04, 95% confidence interval (0.98-1.10), I2 = 0%. CONCLUSION: Cumulative evidence suggests that prior use of ACEIs or ARBs is not associated with a higher risk of COVID-19 or hospitalization due to COVID-19 disease. Our results provide a reassurance to the public not to discontinue prescribed ACEIs/ARBs because of fear of COVID-19.

Fluoroquinolones and the risk of aortopathy: A systematic review and meta-analysis.

OBJECTIVE: To investigate the association between fluoroquinolones use and development of aortopathy. METHODS: A systematic review and meta-analysis was conducted following PRISMA and MOOSE guidelines for reporting systematic reviews of observational studies. Multiple databases were searched and two authors independently screened studies for eligibility. Newcastle Ottawa scale was used to assessed the quality of included studies. Primary outcome of interest was development of aortic aneurysm or dissection among fluoroquinolones users in comparison to non-users. An inverse variance model meta-analysis was used to pool odds ratio or hazards ratio from included studies to calculate the overall effect estimate. Pre specified subgroups analyses were also conducted to explore sources of heterogeneity. RESULTS: Three observational studies that enrolled 941,639 subjects met the inclusion criteria and were included in the final analysis. All studies were of a good methodological quality. Current use of fluoroquinolones, defined as within 60 days from development of the primary outcome, was associated with significantly elevated risk of developing aortic aneurysm and/or dissection in comparison to controls, (OR = 2.04; 95% CI [1.67, 2.48]). There was only a mild degree of between study heterogeneity, I2 = 33%. The association remains robust among all subgroups analyses. CONCLUSION: Our findings indicate that current fluoroquinolone use was significantly associated with increased risk of aortic aneurysm and dissection. Health care providers need to be aware of this serious association and use fluoroquinolones judiciously in order to minimize the risk of the serious sequela of aortopathy.

Workup and Management of Native and Prosthetic Valve Endocarditis.

Infective endocarditis (IE) is associated with significant serious adverse outcomes including death. IE usually presents with diverse clinical picture and syndromic diagnoses including heart failure, stroke, and peripheral embolization. Given variable, vague, and syndromic presentations, the diagnosis of IE may be delayed for days to weeks. Maintaining a high index of suspicion among clinicians is the key to early recognition of the disease and prompt initiation of antimicrobial therapy to prevent IE-associated mortality and morbidity. Blood culture and echocardiography remain essential tools in the diagnosis of infective endocarditis. However, advances in molecular techniques, serology testing, computed tomography scan, and nuclear medicine have led to growth in the available tools that may aid in early diagnosis of infective endocarditis. Antimicrobial agents are the mainstay of IE therapy; however, as many as 50% of endocarditis cases will undergo valve surgery, even on an urgent or emergent basis.

Pattern, duration of stay, and outcomes of medical admissions: a report from teaching community hospital in Assir region, Saudi Arabia.

Background: Population-based studies are the gold standard to understand the burden of different diseases, plan health care policy and resource allocation, and provide an accurate estimate of disease several disease indices including mortality. However, population-based studies are difficult to undertake in a resource-limited situation where no robust data bases and disease registries are available. Therefore, hospital-based cohorts may be used to inform about the community health. Objectives: We sought to study the pattern of disease causing admission, hospital stay, and outcomes of medical admissions to King Abdullah Hospital in Bisha in order to inform clinicians, public health professionals, and policymakers about the current status of diseases within the community in Bisha. Methods:This is a cross-sectional study including all adult patients aged above 18 years who were admitted to King Abdullah Hospital in Bisha, Assir region, to medical services including general internal medicine, general cardiology, nephrology, gastroenterology, rheumatology, and neurology during the study period between 1 June 2015 and 31 May 2016. Common causes of hospital admission, outcomes of hospitalization, and length of stay were estimated and the data were presented as frequency and percentage for categorical valve and mean and standard deviation for continuous variables. Results: Cardiovascular diseases including stroke are considered the leading cause of hospital admission in a teaching community hospital in Bisha, Assir region. Diabetes mellitus and hypertension are prevalent comorbidities among hospitalized patients. Majority of admitted patients have improved and discharged home (83.3%). However, 6.7% were transferred to another facility, 4.1% have left against medical advice, and 5.9% died. Conclusion: Health-related data bases and disease registries are urgently needed to precisely estimate the burden of cardiovascular disease in Assir region in Saudi Arabia. Lifestyle changes, healthy diet, aggressive management of hypertension and diabetes within the community, and allocating necessary resources are urgently to combat the growing burden of cardiovascular disease.

Optimizing Statins and Ezetimibe in Guideline-Focused Management.

Statins are essential medications in the management of patients with clinical atherosclerotic cardiovascular disease, and have been supported by numerous clinical trials. Emerging evidence suggests that adding ezetimibe to statin therapy is associated with a net benefit and improved hard clinical outcomes, particularly in patients with significantly elevated atherosclerotic cardiovascular disease risk and elevated low-density lipoprotein cholesterol levels.

Temporal Trends of High-Intensity Statin Therapy Among Veterans Treated With Percutaneous Coronary Intervention.

BACKGROUND: The 2013 American College of Cardiology/American Heart Association blood cholesterol guideline recommends high-intensity statin therapy among certain groups of patients, but full implementation of the guideline has not yet been satisfactory. We aimed to investigate the temporal trends and predictors of high-intensity statin therapy among veterans who had been treated with percutaneous coronary intervention (PCI) and followed up by cardiologists within the Veterans Health Administrative system. METHODS AND RESULTS: A retrospective cohort study was conducted at the Veterans Health Administrative system including all patients >18 years old who had their PCI procedure between October 2010 and September 2016. National Veterans Health Administrative databases were used to retrieve study participant's demographics, comorbid conditions, statin type and dose within 90 days before and after the PCI procedure. There were 48 862 patients who underwent a PCI procedure during the study period. High-intensity statin use at 90 days post-PCI rose from 23% in 2010 to 37% before release of the 2013 American College of Cardiology/American Heart Association cholesterol guideline, then rose sharply to 80% by 2016. The projected 10-year risk of arteriosclerotic cardiovascular disease events among our study population was projected to be ≈1841 fewer if the cohort had received high-intensity statin therapy versus moderate-intensity statin. CONCLUSIONS: By 2016, the 2013 American College of Cardiology/American Heart Association blood cholesterol guideline was well implemented among veterans who had a PCI procedure in the Veterans Health Administrative system, suggesting systems of care can be improved to increase rates of high-intensity statin initiation.

Impact of total occlusion of culprit artery in acute non-ST elevation myocardial infarction: a systematic review and meta-analysis.

AIMS: Total occlusion (TO) of the culprit artery usually presents with ST-elevation myocardial infarction. A subset of patients with TO present as non-ST segment elevation myocardial infarction (NSTEMI) without classic ST-elevation on the electrocardiogram. This may lead to delay in identification of these patients and further management. We performed a meta-analysis to estimate the difference in outcomes between totally occluded and non-occluded culprit arteries in patients with NSTEMI. METHODS AND RESULTS: Our literature search yielded seven studies with 40 777 patients. The outcomes assessed were clinical presentation (Killip class), left ventricular ejection fraction, time to angiography, major cardiac adverse events (MACE) and all-cause mortality. The generic inverse or Mantel-Haenszel method was used to pool relevant outcomes and the mean difference (MD) or relative risk (RR) was calculated. A total of 10 415 (25.5%) patients had an occluded culprit artery with a predominant infero-lateral distribution (40% right coronary and 33% left circumflex artery). There was an increased risk of both MACE (short-term RR: 1.41; CI: 1.17, 1.70; P = 0.0003; I2 = 26%; medium- to long-term RR: 1.32; CI: 1.11, 1.56; P = 0.001; I2 = 25%) and all-cause mortality (short-term RR: 1.67; CI: 1.31, 2.13; P < 0.0001; I2 = 41%; medium to long-term RR: 1.42; CI: 1.08, 1.86; P = 0.01; I2 = 32%) with TO of the culprit artery. CONCLUSION: Our meta-analysis suggests that patients with NSTEMI who demonstrate a totally occluded culprit vessel on coronary angiography are at higher risk of mortality and major adverse cardiac events. Better risk stratification tools are needed to identify such high-risk acute coronary syndrome patients to facilitate earlier revascularization and potentially to improve outcomes.

Assessment of physicians' awareness and knowledge of familial hypercholesterolemia in Saudi Arabia: Is there a gap?

BACKGROUND: The scarcity of familial hypercholesterolemia (FH) cases reported in Saudi Arabia might be indicative of a lack of awareness of this common genetic disease among physicians. OBJECTIVE: To assess physicians' awareness, practice, and knowledge of FH in Saudi Arabia. METHODS: This is a cross-sectional study conducted among physicians at four tertiary hospitals in Riyadh, Saudi Arabia between March 2016 and May 2016 using a self-administered questionnaire. RESULTS: A total of 294 physicians completed the survey (response rate 90.1%). Overall, 92.9% of the participants have poor knowledge of FH while only 7.1% have acceptable knowledge. The majority (68.7%) of physicians rated their familiarity with FH as average or above average, and these had higher mean knowledge scores than participants with self-reported below average familiarity (mean 3.4 versus 2.6) (P < 0.001). Consultant physicians were 4.2 times more likely to be familiar with FH than residents or registrars (OR = 4.2, 95% CI = 1.9-9.1, P < 0.001). Physicians who currently managed FH patients had higher mean knowledge scores compared to those without FH patients in their care (3.5 versus 2.9) (P = 0.006). In addition, there were statistically significant differences between physicians' mean knowledge scores and their ages, levels of training, and years in practice. Moreover, a substantial deficit was identified in the awareness of various clinical algorithms to diagnose patients with FH, cascade screening, specialist lipid services, and the existence of statin alternatives, such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. CONCLUSION: A substantial deficit was found in the awareness, knowledge, practice, and detection of FH among physicians in Saudi Arabia. Extensive educational programs are required to raise physician awareness and implement best practices; only then can the impact of these interventions on FH management and patient outcome be assessed.

The Use of Statins and Risk of Community-Acquired Pneumonia.

PURPOSE OF THE REVIEW: Community-acquired pneumonia (CAP) is still associated with a large burden and causes significant morbidity and mortality. Besides universal vaccination and antibiotic treatment, statins as adjunctive therapy may also have a beneficial role in the prevention and treatment of CAP. Our goal from this review is to discuss the epidemiology of CAP, and role of statins as adjunctive therapy in the development of CAP. RECENT FINDINGS: Statins are lipid-lowering medications characterized by their ability to control hypercholesterolemia in addition to other pleiotropic effects that could explain their role in the pathogenesis of CAP. While most observational studies have shown that statins reduce risk of pneumonia in the general population, patients with diabetes, and recently in patients with myocardial infarction, no randomized controlled trial (RCT) to date has been conducted to assess the efficacy of statins to prevent development of CAP. Given the paucity of robust randomized evidence to assess statin use and the development of CAP, and considering conflicting results of the observational studies, we are not in favor of initiation of statins for either the prevention or treatment of CAP.

Indications of Surgery in Infective Endocarditis.

PURPOSE OF THE REVIEW: Infective endocarditis (IE) is a serious disease with significant morbidity and mortality. Valve surgery is fundamental in the standard of care of selected IE patients. Indeed, valve surgery can be a lifesaving procedure in critically ill endocarditis patients. Our goal from this review is to discuss the indications of surgery in IE population and international cardiac societies' guideline recommendations. RECENT FINDINGS: Though IE is an uncommon disease, its incidence is noted to be on rise in some parts of the world, and the disease is expected to continue to be a major health problem. Antimicrobials remain the mainstay of IE therapy, but as many as 50% of endocarditis patients will undergo surgical intervention. Heart failure most commonly from acute valvular insufficiency, uncontrolled and persistent infection, and recurrent embolic events are the major indications for valve surgery in IE population. Heart failure is by far the most common indication for surgery in IE patients. Despite the fact that many IE patients will require surgical interventions, most of the international societies' recommendations to perform valve surgery are based on observational studies or experts' opinion. Surgery plays a major role in the management of IE patients, and it is most commonly performed in patients with heart failure, persistent or uncontrolled infection, and recurrent emboli. Most of the current evidence supporting surgical intervention in IE patients is based on observational studies and experts' opinion. Randomized clinical trials are urgently needed to guide surgical therapy in IE.

Coronary artery calcium score as a predictor for incident stroke: Systematic review and meta-analysis.

BACKGROUND: Coronary artery calcium score (CACS) is a well-established test for risk stratifying asymptomatic patients for overall cardiovascular or coronary events. However; the prognostic value for incident stroke remains controversial. The objective of this study was to investigate the predictive value of CACS obtained by non-contrast electrocardiogram-gated computed tomography for incident stroke. METHODS: We searched PubMed, EMBASE, Cochrane databases for prospective longitudinal studies of CACS which reported the incidence of stroke. Incidence of stroke was compared in patients with and without coronary calcification. RESULTS: Three studies evaluated 13,262 asymptomatic patients (mean age=60years, 50% men) without apparent cardiovascular diseases. During a follow-up of 7.2years (median 5years, range 4.4-9.5years, 95,434patient-years), the overall pooled incidence of stroke was 0.26%/year. The pooled risk ratio of CACS>0 for incident stroke was 2.95 (95% CI: 2.18-4.01, p<0.001) compared to CACS=0. The heterogeneity among studies was low (I2=0%). The pooled incidence rate of stroke categorized by CACS was 0.12%/year for CACS 0, 0.26%/year for CACS 1-99, 0.41%/year for CACS 100-399 and 0.70%/year for CACS ≥400. CONCLUSIONS: In asymptomatic patients without apparent cardiovascular diseases, the incidence of stroke was overall low. The presence and severity of coronary artery calcification were associated with incident stroke over mid-long term follow-up.

Atypical Presentation of C. Difficile Infection: Report of a Case with Literature Review.

Clostridium difficile (C. difficile) is a gram-positive, obligate, anaerobic spore-forming bacillus first reported by Hall and O'Toole in 1935. It occurs mostly after antibiotic use and invariably presents with watery diarrhea. We describe an atypical presentation of C. difficile in a 64-year-old Caucasian female who presented to the our emergency department with abdominal pain, nausea, and vomiting for one day. A complete blood count revealed leukocytosis 30 x 10(9)/L and a subsequent computed tomography (CT) scan of the abdomen and the pelvis, showed fluid filled small bowel loops consistent with enteritis. Her presentation was unusual for lack of diarrhea, the hallmark of C. difficile infection. She was admitted and treated with oral vancomycin. The polymerase chain reaction (PCR) value in the stool for C. difficile was positive. The patient responded very well: her abdominal pain resolved and leukocyte count normalized after a few doses of vancomycin (125 mg po qid). The patient's progress was followed in our clinic for the last three months.

Efficacy and safety of transcatheter aortic valve replacement in intermediate surgical risk patients: A systematic review and meta-analysis.

BACKGROUND: The efficacy of transcatheter aortic valve replacement (TAVR) in aortic stenosis patients at high surgical risk has been established. The data on patients with intermediate risk is not conclusive. We performed a meta-analysis of studies which compared TAVR with surgical aortic valve replacement (SAVR) in patients at intermediate surgical risk. METHODS: Several databases searched from inception to February 2015 yielded 7 eligible studies with 2,173 participants. The measured outcome of efficacy was all-cause mortality. Data on safety included stroke, permanent pacemaker implantation (PPI), aortic regurgitation (AR), vascular access complications, and major bleeding. Outcomes were pooled and relative risk (RR) was calculated with the Mantel-Haenszel method. RESULTS: There was no difference in either short-term (RR, 1.02; 95% CI: 0.63-1.63; P = 0.94; I2 = 0%) or medium to long-term all-cause mortality (RR, 0.99; 95% CI: 0.81-1.21; P = 0.91; I2 = 0%). There was increased incidence of stroke (RR, 2.96; 95% CI: 0.87-10.09; P = 0.08; I2 = 0%), AR (RR, 3.59; 95% CI: 2.13-7.19; P < 0.00001; I2 = 2%), PPI (RR, 6.53; 95% CI: 1.91-22.32; P < 0.003; I2 = 0%) and vascular access complications (RR, 3.84; 95% CI: 0.65-22.76; P < 0.14; I2 = 48%) in patients with TAVR. There was a small, albeit increased risk of major or life threatening bleeding with SAVR as compared to TAVR (RR, 1.36; 95% CI: 1.04-1.80; P < 0.03; I2 = 0%). CONCLUSIONS: In this meta-analysis we found that TAVR may be an acceptable alternative to SAVR in patients with intermediate risk for surgery. However, we must await evidence from the current large randomized trials before widespread adoption of this procedure is undertaken. © 2016 Wiley Periodicals, Inc.

Does Ondansetron Modify Sympathectomy Due to Subarachnoid Anesthesia?: Meta-analysis, Meta-regression, and Trial Sequential Analysis.

BACKGROUND: Disagreement among many underpowered studies has led to an equivocal understanding of the efficacy of the 5-HT3 antagonist ondansetron in preventing the consequences of sympathectomy after subarachnoid anesthesia. The authors assessed the efficacy of ondansetron with respect to the overall quality and statistical power of the meta-analyses. METHODS: The authors used a standard and a newer method of meta-analysis, trial sequential analysis (TSA), to estimate adjusted CIs based on how much information has been accrued. They also used random-effects meta-analyses techniques, small trial bias assessment, selection models, sensitivity analyses, and the Grading of Recommendations on Assessment, Development, and Evaluation system. These results from the aforementioned techniques were compared, and importance of consideration of these factors was discussed. RESULTS: Fourteen randomized placebo-controlled trials (1,045 subjects) were identified and analyzed. By using conventional meta-analyses, the authors determined that ondansetron was associated with reduction in the incidence of hypotension (relative risk = 0.62 [95% CI, 0.46 to 0.83], P = 0.001; TSA-adjusted CI, 0.34 to 1.12; I = 60%, P = 0.002) and bradycardia (relative risk = 0.44 [95% CI, 0.26 to 0.73], P = 0.001; TSA-adjusted CI, 0.05 to 3.85; I = 0%, P = 0.84). However, the authors found indications of bias among these trials. TSAs demonstrated that the meta-analysis lacked adequate information size and did not achieve statistical significance when adjusted for sparse data and repetitive testing. The Grading of Recommendations on Assessment, Development, and Evaluation system showed that the results had low to very low quality of evidence. CONCLUSIONS: The analyses fail to confirm evidence that ondansetron reduces the incidence of hypotension and bradycardia after subarachnoid anesthesia due to the risk of bias and information sizes less than the required. As results from meta-analysis are given significant weight, it is important to carefully evaluate the quality of the evidence that is input.