The diagnostic and prognostic value of near-normal perfusion or borderline ischemia on stress myocardial perfusion imaging.

BACKGROUND: Data on the diagnostic and prognostic value of subtle abnormalities on myocardial perfusion imaging (MPI) are limited. METHODS AND RESULTS: In a retrospective single-center cohort of patients who underwent regadenoson SPECT-MPI, near-normal MPI was defined as normal left ventricular ejection fraction (LVEF ≥ 50%) and a summed stress score (SSS) of 1-3 vs SSS = 0 in normal MPI. Borderline ischemia was defined as normal LVEF, SSS = 1-3, and a summed difference score (SDS) of 1 vs SDS = 0 in the absence of ischemia. Coronary angiography data within 6 months from MPI were tabulated. Patients were followed for cardiac death (CD), myocardial infarction (MI), coronary revascularization (CR), and Late CR (LCR) [> 90 days post MPI]. Among 6,802 patients (mean age, 62 ± 13 years; 42% men), followed for a mean of 2.5 ± 2.1 years, 4,398 had normal MPI, 2,404 had near-normal MPI, and 972 had borderline ischemia. Among patients who underwent angiography within 6 months, obstructive (≥ 70% or left main ≥ 50%) CAD was observed at higher rates among subjects with near-normal MPI (33.5% vs 25.5%; P = .049) and those with borderline ischemia (40.5% vs 25.8%; P = .004). During follow-up, 158 (2.3%) CD/MI, 246 (3.6%) CR, and 150 (2.2%) LCR were observed. Near-normal MPI (SSS = 1-3), compared to normal MPI (SSS = 0), was not associated with a significant difference in the risk of the composite endpoint of CD/MI (Hazard ratio [HR], 1.21; 95% confidence interval [CI], .88-1.66; P = .243) or LCR (HR 1.28; CI .93-1.78; P = .130), but was associated with a significant increase in the risk of CR (HR 1.91; CI 1.49-2.46; P < .001). Borderline ischemia (SDS = 1), compared to no ischemia (SDS = 0), was not associated with a significant difference in the risk of CD/MI [HR 1.09; CI .70-1.69; P = .693], but was associated with a significant increase in the risk of CR (HR 5.62; CI 3.08-10.25; P < .001) and LCR (HR 2.98; CI 1.36-6.53; P = .006). CONCLUSION: Near-normal MPI and borderline ischemia on SPECT-MPI provide no significant prognostic information in predicting hard cardiac events but are associated with higher rates of obstructive angiographic CAD and coronary revascularizations.

The prognostic utility of regadenoson SPECT myocardial perfusion imaging in patients with end-stage renal disease: The largest cohort to date.

BACKGROUND: There are limited data on the prognostic utility of regadenoson SPECT myocardial perfusion imaging (MPI) in patients with end-stage renal disease (ESRD). METHODS AND RESULTS: In a single-center, retrospective study, we analyzed consecutive ESRD patients who underwent regadenoson SPECT-MPI. The severity of MPI abnormalities and ischemic burden were determined quantitatively. The primary endpoint was major adverse cardiac events (MACE), defined as the composite of cardiac death or myocardial infarction. Among 1,227 subjects (mean age 54 ± 13 years, 47% men), 60 (5%) MACE were observed during a mean follow-up of 2.5 ± 1.8 years. The presence and severity of MPI abnormalities and ischemic burden were associated with a stepwise increase in MACE risk. Abnormal MPI (SSS ≥ 4) was associated with increased MACE risk, independent and incremental to relevant clinical covariates; adjusted hazard ratio, 1.95; 95% confidence interval, 1.15-3.32; Δχ2 = 5.97; P = .013. Myocardial ischemia (SDS ≥ 2) was associated with a trend towards increased MACE risk; adjusted hazard ratio, 1.63; 95% confidence interval, 0.96-2.77; Δχ2 = 3.12; P = .072. CONCLUSION: In the largest cohort to date, we demonstrated the incremental prognostic value of abnormal MPI in predicting MACE risk in ESRD patients. Given its size, our study provides improved risk estimates in this population compared to previous reports.

The prognostic value of regadenoson SPECT myocardial perfusion imaging: The largest cohort to date.

BACKGROUND: Data on the prognostic value of regadenoson SPECT myocardial perfusion imaging (MPI) is limited and based on small cohorts. METHODS AND RESULTS: We conducted a single-center, retrospective cohort study of 10,275 consecutive patients who underwent regadenoson SPECT-MPI. Among the study subjects, 28.7% had abnormal MPI and 25.5% had myocardial ischemia. Patients were followed for a mean of 2.4 ± 2.2 years for major adverse cardiac events (MACE), defined as cardiac death or myocardial infarction. There was a significant stepwise increase in MACE with an increasing burden of perfusion abnormality (P < .001) and myocardial ischemia (P < .001). Abnormal MPI (adjusted HR 1.52; 95% CI 1.21 to 1.91) and myocardial ischemia (adjusted HR 1.53; 95% CI 1.25 to 1.89) were associated with MACE, independent of and incremental to clinical covariates and left ventricular ejection fraction (LVEF). Moreover, post-stress LVEF, LVEF reserve, and left ventricular end-diastolic volume added significant prognostic information. Transient ischemic dilation ≥ 1.31 did not provide incremental prognostic value (adjusted HR 1.02; P = .906). CONCLUSION: In the largest cohort to date, we demonstrated that the presence and severity of perfusion abnormality and myocardial ischemia on regadenoson stress SPECT-MPI are associated with an independent increase in MACE.

Prognostic significance of ischemic electrocardiographic changes with regadenoson stress myocardial perfusion imaging.

BACKGROUND: In patients undergoing regadenoson SPECT myocardial perfusion imaging (MPI), the prognostic value of ischemic ST-segment depression (ST↓) and the optimal ST↓ threshold have not been studied. METHODS: A retrospective cohort study of consecutive patients referred for regadenoson stress MPI was conducted. Patients with uninterpretable ECG were excluded. Two diagnostic thresholds of horizontal or downsloping ST↓ were studied, ≥ 0.5 mm and ≥ 1.0 mm. The primary endpoint was the composite major adverse cardiac events (MACE) of cardiac death, myocardial infarction, or coronary revascularization. RESULTS: Among 8615 subjects (mean age 62 ± 13 years; 55% women), 89 (1.0%) had ST↓ ≥ 1.0 mm and 133 (1.5%) had ST↓ ≥ 0.5 mm. Regadenoson-induced ST↓ was more common in women (P < .001). Mean follow-up was 2.5 ± 2.2 years. After multivariate adjustment, ST↓ ≥ 1.0 mm was associated with a non-significant increase in MACE risk (P = .069), irrespective to whether MPI was abnormal (P = .162) or normal (P = .214). Ischemic ST↓ ≥ 0.5 mm was independently associated with MACE in the entire cohort (HR 2.14; CI 1.38-3.32; P = .001), whether MPI is normal (HR 2.07; CI 1.07-4.04; P = .032) or abnormal (HR 2.24; CI 1.23-4.00; P = .007), after adjusting for clinical and imaging covariates. An ST↓ threshold of ≥ 0.5 mm provided greater incremental prognostic value beyond clinical and imaging parameters (Δχ2 = 12.78; P < .001) than ≥ 1.0 mm threshold (Δχ2 = 3.72; P = .093). CONCLUSION: Regadenoson-induced ischemic ST↓ is more common in women and it provides a modest independent prognostic value beyond MPI and clinical parameters. ST↓ ≥ 0.5 mm is a better threshold than ≥ 1.0 mm to define ECG evidence for regadenoson-induced myocardial ischemia.

Optimizing lung cancer classification through hyperparameter tuning.

Artificial intelligence is steadily permeating various sectors, including healthcare. This research specifically addresses lung cancer, the world's deadliest disease with the highest mortality rate. Two primary factors contribute to its onset: genetic predisposition and environmental factors, such as smoking and exposure to pollutants. Recognizing the need for more effective diagnosis techniques, our study embarked on devising a machine learning strategy tailored to boost precision in lung cancer detection. Our aim was to devise a diagnostic method that is both less invasive and cost-effective. To this end, we proposed four methods, benchmarking them against prevalent techniques using a universally recognized dataset from Kaggle. Among our methods, one emerged as particularly promising, outperforming the competition in accuracy, precision and sensitivity. This method utilized hyperparameter tuning, focusing on the Gamma and C parameters, which were set at a value of 10. These parameters influence kernel width and regularization strength, respectively. As a result, we achieved an accuracy of 99.16%, a precision of 98% and a sensitivity rate of 100%. In conclusion, our enhanced prediction mechanism has proven to surpass traditional and contemporary strategies in lung cancer detection.

Comparison of Outcomes Between Right and Left Upper Extremity Access in Endovascular Aortic Repair for Patients with Thoracoabdominal and Abdominal Aortic Aneurysms: A Systematic Review and Meta-Analysis.

Traditionally, left-sided upper extremity (LUE) access has been preferred in patients undergoing endovascular aortic repair (EVAR) to manage aortic aneurysms and decrease the risk of cerebrovascular adverse events. Recently, right-sided upper extremity access (RUE) has gained popularity owing to its greater maneuverability and ergonomics. However, synthesized data comparing the safety and efficacy of RUE and LUE accesses are limited. A comprehensive literature search was conducted on various databases from inception to September 2023 to retrieve all studies that compared RUE and LUE access in EVAR. Data on stroke, 30-day mortality, technical success, access-site complications, total time required for fluoroscopy, and contrast agent requirement were extracted, pooled, and analyzed. Forest plots were generated using a random-effects model on review manager by pooling the risk ratios (RRs) and standard mean differences (SMDs). Ten observational studies with a total of 3994 patients were included in our analysis with 1186 patients in the RUE and 2808 patients in the LUE access groups. EVAR using RUE access was associated with a significantly lower amount of contrast agent requirement than the LUE access group [SMD, -0.23; 95% confidence interval (CI), -0.45 to -0.02; P = 0.03]. There was no significant difference between the 2 groups in terms of the risk of stroke (RR, 1.62; 95% CI, 0.81-3.22; P = 0.17), 30-day mortality (RR, 1.42; 95% CI, 0.50-4.06; P = 0.51), rate of technical success (RR, 0.98; 95% CI, 0.95-1.01; P = 0.18), risk of access-site complications (RR, 1.00; 95% CI, 0.72-1.39; P = 0.99), and total time required for fluoroscopy (SMD, 0.07; 95% CI, -0.39 to 0.26; P = 0.69). The use of RUE access in EVAR appears to be comparable to LUE access in terms of the risk of stroke, access-related complications, all-cause mortality, technical success rate, and fluoroscopy duration. The RUE group required a lower volume of contrast agent.

Exploring Acute Kidney Injury Following Aortic Dissection: A Comprehensive Review of Machine Learning Models for Predicting Risk, Management Strategies, Complications, and Racial and Gender Disparities.

Both types of aortic dissection (AD), Stanford type A and type B, can result in complications such as acute kidney injury (AKI) and aortic rupture. Renal complications in AD arise from compromised renal perfusion affecting the renal arteries. Understanding the intricate connection between AD and AKI is crucial for navigating the complexities of tailored treatment and formulating specific management plans. Concerning machine learning models, in patients with type A aortic dissection, factors such as decreased platelet count on admission, increased D-dimer level, longer cardiopulmonary bypass duration, elevated white blood cell levels, the need for blood transfusion, longer aortic clamp time, extended surgery duration, advanced age, and an elevated body mass index were positively associated with the development of AKI. For the risk of AKI after type B aortic dissection, elevated Nt-pro brain natriuretic peptide, prolonged activated partial thromboplastin time, elevated admission systolic blood pressure, and a higher contrast agent requirement during operative repair were found to predict the risk. Male gender was associated with a higher risk of AKI, and nonwhite race was linked to a higher risk of AKI, a greater likelihood of requiring more urgent procedures, and lower levels of insurance coverage. The treatment of AKI following AD requires a multifaceted approach. Identifying and addressing the underlying cause, such as low blood pressure, renal artery involvement, or medication-induced injury, is crucial for effective management and preventing further kidney damage. Maintaining proper fluid balance is essential for improving renal perfusion, but careful monitoring is necessary to avoid complications. The evolving landscape of research, particularly in biomarkers and AI programs, reveals a promising role in predicting the risk for and managing AKI post-AD.

Mortality and in-patient outcomes in pheochromocytoma patients with hypertensive emergency in the United States: A propensity score matched analysis.

INTRODUCTION: Pheochromocytoma is a rare cause of hypertensive emergency. The objective of this analysis was to compare the clinical characteristics, comorbidities, and in-hospital outcomes of patients admitted with hypertensive emergencies with and without co-existing pheochromocytoma. METHODS: A retrospective analysis of the National Inpatient Sample (NIS) Database from 2016 to 2020 was conducted, encompassing 640,395 patients hospitalized for hypertensive emergencies, including 2535 patients diagnosed with pheochromocytoma. We compared demographics, comorbidities, in-hospital outcomes and resource utilization metrics in patients with and without pheochromocytoma. Propensity-score matching was utilized to account for potential confounders and risk of complications was compared. RESULTS: Among the pheochromocytoma cohort (51.9% female), a significant portion (35.7%) were under 50 years of age, with the majority being Caucasian (47.9%). Comorbid conditions such as obesity, diabetes, and smoking were prevalent, with notable differences in cancer (7.5% vs. 2.3%, p < 0.001) and peripheral vascular disease (17% vs. 8.2%, p < 0.001) rates compared to the non-pheochromocytoma cohort. Pheochromocytoma patients had a longer hospital stay (7.5 vs. 6 days, p = 0.002) and higher odds of acute kidney injury (AKI) (1.54, 1.18-2, p=0.001) but lower odds of requiring hemodialysis (0.52, 0.32-0.79, p < 0.001) or experiencing major cardiovascular events (0.5, 0.36-0.69, p < 0.001). No significant difference in inflation-adjusted hospitalization costs was found between the groups. CONCLUSIONS: Patients with hypertensive emergencies and pheochromocytoma had a higher incidence of AK, certain comorbidities (cancer, peripheral vascular disease), and more complex hospital courses suggested by longer length of stay. However, the overall cost of hospitalization did not significantly differ between the two cohorts.

Primary cardiac sarcoma: demographics, genomic study correlation, and survival benefits of surgery with adjuvant therapy in U.S. population.

BACKGROUND: Cardiac sarcomas are rare and aggressive tumors with little known about the demographics, genetics, or treatment outcomes. OBJECTIVES: The objectives of this study were to characterize the demographics, treatment modality, and survival associated with cardiac sarcomas and evaluate the potential for mutation-directed therapies. METHODS: All cases from 2000 to 2018 of cardiac sarcoma were extracted from the SEER database. Genomic comparison utilized The Cancer Genome Atlas (TCGA) database, as well as reviews and re-analysis of past applicable genomic studies. RESULTS: Cardiac sarcomas occurred most often in White patients, compared with national census data cardiac sarcomas occurred at a significantly higher rate in Asians. The majority of cases were undifferentiated (61.7%) and without distant metastases (71%). Surgery was the most common primary treatment modality and offered survival benefit (HR 0.391 (p = 0.001) that was most pronounced and sustained as compared to patients who received chemotherapy (HR 0.423 (p = 0.001) or radiation (HR 0.826 (p = 0.241) monotherapy. There was no difference in survival when stratified by race or sex; however, younger patients (< 50) had better survival. Genomics data on histologically undifferentiated cardiac sarcomas revealed a significant number were likely poorly differentiated pulmonary intimal sarcomas and angiosarcomas. CONCLUSIONS: Cardiac sarcoma is a rare disease with surgery continuing to be a cornerstone of therapy followed by traditional chemotherapy. Case studies have indicated the potential for therapies directed to specific genetic aberrations to improve survival for these patients and utilization of next-generation sequencing (NGS) will help improve both classification and these therapies for cardiac sarcoma patients.

Frequency and Predictors of Radial Artery Occlusion in Patients Undergoing Percutaneous Coronary Intervention.

Background and objective Transradial access (TRA) has become the preferred route for percutaneous coronary interventions (PCI), and this site is often a chink in the armor for staged PCI. In this study, we aimed to evaluate the incidence and predictors of radial artery occlusion (RAO) after TRA. Methods We conducted a retrospective study involving 1,307 patients who underwent PCI at the Tabba Heart Institute (THI) in Karachi, Pakistan from August 2018 to June 2019. TR band was used for hemostasis after PCI. Results The primary outcome of our study was RAO, which was observed in 11.3% of the study subjects. On multivariate analysis, female gender [odds ratio (OR): 1.79, 95% CI: 1.21-2.64], cardiovascular instability (OR: 2.5, 95% CI: 1.22-5.11), dyslipidemia (OR: 0.61, 95% CI: 0.4-0.92), and a higher number of diseased vessels were found to be predictors of RAO (p=0.004). Conclusion RAO is often an asymptomatic complication of TRA. To ensure radial artery patency, a carefully thought-out management plan and follow-up must be devised for high-risk patients.

Frequency, Risk Factors, and Outcome of Definite Stent Thrombosis: A Single-Center Experience.

Introduction Stent thrombosis (ST) is a serious and potentially life-threatening complication of primary or complex high-risk percutaneous coronary intervention (PCI). Multiple factors are said to precipitate ST, related to the patient's clinical comorbidities, lesion characteristics, operative technique, and post-procedural care. The older-generation stents were thought to be involved in early ST. Though the new generation of drug-eluting stents decreases the incidence of early and late ST, patients are still at risk of very late stent thrombosis (VLST). Objective To evaluate the frequency, risk factors, and outcomes of definite ST in developing and resource-constrained countries like Pakistan, where PCIs, including primary PCI, complex PCI, and PCI in high-risk populations, are performed routinely. Methods This observational cross-sectional study included all patients who underwent primary and complex high PCI between 2012 and 2017 at TABBA Heart Institute (THI), Karachi, Pakistan. Results We included a total of 6587 patients in our study, and among the enrolled sample size, 22 (0.33%) had definite ST. Acute stent thrombosis (AST) was found in seven patients, sub-acute stent thrombosis (SAST) in 10, late stent thrombosis (LST) in two, and VLST were observed in three patients. The basic characteristics of our study ST population were as follows: mean age was 58 years, 95.5% were male, 4.5% were female, nine patients (40%) had diabetes mellitus, 15 patients (68%) had hypertension, 11 (50%) had dyslipidemia, and four patients were smokers (18%). Conclusion The frequency, risk factors, and rate of mortality of definite ST in the Pakistani population who underwent primary and complex high-risk PCI reflect nearly equal statistics observed in other studies. As seen in other international studies, the incidence rate of VLST was higher in our population.

Anomalous Origin of the Right Coronary Artery From the Mid-Portion of the Left Anterior Descending Artery.

Coronary artery anomalies (CAAs) are rare findings and usually diagnosed incidentally on coronary angiograms for other cardiac conditions in most cases. However, coronary anomalies are being increasingly reported with the invention of more advanced cardiac imaging techniques. The CT of the heart structure is the best modality to diagnose and track the exact course of the anomalous artery and to guide in proper management. Anomalous course of the right coronary artery (RCA) between the aorta and pulmonary artery may cause compression and require surgical intervention given the risk of myocardial ischemia and sudden death. In this report, we discuss the case of a 69-year-old female with no prior cardiac comorbidities. The patient had been referred from the primary care office for cardiac clearance to undergo bilateral knee replacement surgery. On further inquiry, she reported a history of murmur and stated that she had been having dyspnea on exertion over the last six months. Precordial examination revealed a 2/6 ejection systolic murmur. Transthoracic echocardiogram showed severe aortic stenosis. For further evaluation, she underwent a coronary angiogram, which showed right dominant coronary system, normal left main with no stenosis, a large septal branch that had anomalously originated from left main and coursing all the way to the apex, and the RCA originating from the mid-portion of the left descending artery. The cardiac CT scan showed the exact course of the anomalous origin of the RCA from the mid-left anterior descending artery (LAD). The RCA coursed anteriorly to the main pulmonary artery/right ventricular outflow tract to reach the right atrioventricular groove. The patient underwent transcatheter aortic valve replacement (TAVR) and was discharged in stable condition.

Frequency of Non-ST Segment Elevation Myocardial Infarction (NSTEMI) in Acute Coronary Syndrome With Normal Electrocardiogram (ECG): Insights From a Cardiology Hospital in Pakistan.

Introduction Patients presenting to the emergency department with a non-ST segment elevation myocardial infarction (NSTEMI) frequently have unremarkable electrocardiography (ECG) reports, alluding to the unreliable nature of ECG in diagnosing NSTEMI. This study aims to assess the burden of NSTEMI in acute coronary syndrome (ACS) with unremarkable ECG, elucidating that in patients presenting with acute retrosternal chest pain, NSTEMI should not be excluded unless cardiac enzyme levels are assessed. Methods All patients who fulfilled the inclusion criteria in the Department of Cardiology, Tabba Heart Institute, Karachi were included. After obtaining informed written consent, a detailed history was taken. Clinical examination was consequently performed, and an ECG, along with the cardiac enzymes implicated in ACS, such as troponin I, was evaluated. The proportion of normal ECGs in the context of an NSTEMI was duly noted. Result A total of 215 patients with ACS presenting within 24 hours of the onset of symptoms, on a background of unremarkable ECG reports, were included. One hundred thirty-eight (64.2%) were males and 77 (35.8%) were females, with the mean age being 54.3 + 7.6 years. A confirmed diagnosis of NSTEMI was made in 49 (22.8%) of the total cases. Conclusion The frequency of patients presenting with an NSTEMI within 24 hours of the onset of symptoms, and having normal ECG findings, was strikingly high in patients presenting to the Tabba Heart Institute, Karachi, Pakistan. These findings were more common in males and in older patients.

Thrombolysis in Myocardial Infarction (TIMI) Risk Score Assessment for Complications in Acute Anterior Wall ST Elevation Myocardial Infarction.

Introduction and objective Effective risk stratification is integral to the management of acute coronary syndromes. The Thrombolysis in Myocardial Infarction (TIMI) risk score for ST-segment elevation myocardial infarction (STEMI) is based on eight high-risk parameters that can be used at the bedside for risk stratification of patients presenting with STEMI. This study was designed to determine the frequency of cardiac complications of anterior wall STEMI assessed on TIMI risk score and to compare the rate of cardiac complications according to the TIMI score. Materials and methods An observational case series study was conducted in the Department of Cardiology at Sandeman Provincial Hospital in Quetta, Pakistan. The study duration was six months, from September 22, 2016 to March 23, 2017. A total of 369 patients were selected who had anterior wall myocardial infarction and received thrombolytic therapy, according to the inclusion and exclusion criteria. The TIMI score was calculated by proforma at the time of admission. Patients were divided into three groups: low-risk, moderate-risk, and high-risk TIMI groups. The frequency of complications of anterior wall myocardial infarction at the time of discharge was compared among these groups. Results The study included 285 male patients (77.2%) and 84 (22.8%) female patients. A total of 174 (47.2%) patients were smokers, 79 (21.4%) were obese, and 93 (25.2%) had hyperlipidemia. Of the 369 patients, 205 (55.6%) were included in the low-risk group, 150 (40.7%) in the moderate-risk group, and 14 (3.8%) in the high-risk group. Post-myocardial infarction arrhythmias were noted in 33 (16.09%) patients in the low-risk group and six (4%) patients in the moderate-risk group. Left ventricular dysfunction was noted in 158 (77.07%) patients in the low-risk group, 78 (52%) patients in the moderate-risk group, and seven (50%) patients in the high-risk group. Cardiogenic shock occurred in seven (3.41%) patients in the low-risk group, 47 (31.33%) patients in the moderate-risk group, and 0 (0%) patient in the high-risk group. Death occurred in seven (3.41%) patients in the low-risk group, 19 (12.66%) patients in the moderate-risk group, and seven (50%) patients in the high-risk group. Conclusion TIMI scoring provides a better assessment in terms of complications caused by STEMI. The complications include the mechanical and electrophysiology of the heart.

Efficacy of Allopurinol in Cardiovascular Diseases: A Systematic Review and Meta-Analysis.

BACKGROUND: Given current evidence, the use of allopurinol for the prevention of major cardiovascular events (acute cardiovascular syndrome (ACS) or cardiovascular mortality) in patients undergoing coronary artery bypass graft (CABG), after index ACS or heart failure remains unknown. METHODS: Multiple databases were queried to identify studies comparing the efficacy of allopurinol in patients undergoing CABG, after ACS or heart failure. The unadjusted odds ratio (OR) was calculated using a random effect model. RESULTS: A total of nine studies comprising 850 patients (allopurinol 480, control 370) were identified. The pooled OR of periprocedural ACS (OR: 0.25, 95% confidence interval (CI): 0.06 - 0.96, P = 0.05) and cardiovascular mortality (OR: 0.22, 95% CI: 0.07 - 0.71, P = 0.01) was significantly lower in patients receiving allopurinol during CABG compared to patients in the control group. The overall number needed to treat (NNT) to prevent one ACS event was 11 (95% CI: 7 - 28), while the NNT to prevent one death was 24 (95% CI: 13 - 247). By contrast, the odds of cardiovascular mortality in the allopurinol group were not significantly different from the control group in patients on long-term allopurinol after ACS or heart failure (OR: 0.33, 95% CI: 0.01 - 8.21, P = 0.50) and (OR: 1.12, 95% CI: 0.39 - 3.20, P = 0.83), respectively. Similarly, the use of allopurinol did not reduce the odds of recurrent ACS events at 2 years (OR: 0.32, 95% CI: 0.03 - 3.18, P = 0.33). CONCLUSIONS: Periprocedural use of allopurinol might be associated with a significant reduction in the odds of ACS and cardiovascular mortality in patients undergoing CABG. Allopurinol, however, offers no long-term benefits in terms of secondary prevention of ACS or mortality. Larger scale studies are needed to validate our findings.