Relationship between sexual differences and cardiovascular risk factors in the prevalence of asymptomatic coronary disease.

BACKGROUND: This study investigated the sexual differences of coronary artery disease (CAD) prevalence and its association with cardiovascular risk factors in the asymptomatic population. METHODS: In total 6434 asymptomatic participants without known CAD (1740 women and 4694 men) underwent coronary computed tomography angiography (CCTA). The prevalence of significant CAD (diameter stenosis ≥50%) and other CCTA findings were compared by sex, and its influence on CAD was investigated in groups stratified by the number of cardiovascular risk factors, including age (>55 years), hypertension, diabetes, dyslipidemia, and current smoking. RESULTS: The prevalence of current smokers, hypertension, and diabetes were higher in men than women. The mean coronary artery calcium score was 13.1 ± 58.4 for women and 51.1 ± 158.2 for men; the coronary atherosclerosis burden indices were significantly higher in men than women. Significant CAD was identified in 65 women (3.7%) and 429 men (9.1%), showing a significant association (adjusted odds ratio [OR] 2.38, P < 0.001). The relatively higher risk for significant CAD in men was observed in patients with fewer risk factors, and the risk difference was not significant in patients with many risk factors (adjusted ORs: 7.69, 3.37, 1.71, 1.31, and 0.88 in patients with 0, 1, 2, 3, and 4-5 risk factors, respectively). The association between sex and risk factor groups was significant (P < 0.001). CONCLUSIONS: In the asymptomatic population, a significantly higher CAD prevalence was noted in men than women. However, women with a high number of cardiovascular risk factors showed a CAD prevalence similar to that of men.

Routine Functional Testing or Standard Care in High-Risk Patients after PCI.

BACKGROUND: There are limited data from randomized trials to guide a specific follow-up surveillance approach after myocardial revascularization. Whether a follow-up strategy that includes routine functional testing improves clinical outcomes among high-risk patients who have undergone percutaneous coronary intervention (PCI) is uncertain. METHODS: We randomly assigned 1706 patients with high-risk anatomical or clinical characteristics who had undergone PCI to a follow-up strategy of routine functional testing (nuclear stress testing, exercise electrocardiography, or stress echocardiography) at 1 year after PCI or to standard care alone. The primary outcome was a composite of death from any cause, myocardial infarction, or hospitalization for unstable angina at 2 years. Key secondary outcomes included invasive coronary angiography and repeat revascularization. RESULTS: The mean age of the patients was 64.7 years, 21.0% had left main disease, 43.5% had bifurcation disease, 69.8% had multivessel disease, 70.1% had diffuse long lesions, 38.7% had diabetes, and 96.4% had been treated with drug-eluting stents. At 2 years, a primary-outcome event had occurred in 46 of 849 patients (Kaplan-Meier estimate, 5.5%) in the functional-testing group and in 51 of 857 (Kaplan-Meier estimate, 6.0%) in the standard-care group (hazard ratio, 0.90; 95% confidence interval [CI], 0.61 to 1.35; P = 0.62). There were no between-group differences with respect to the components of the primary outcome. At 2 years, 12.3% of the patients in the functional-testing group and 9.3% in the standard-care group had undergone invasive coronary angiography (difference, 2.99 percentage points; 95% CI, -0.01 to 5.99), and 8.1% and 5.8% of patients, respectively, had undergone repeat revascularization (difference, 2.23 percentage points; 95% CI, -0.22 to 4.68). CONCLUSIONS: Among high-risk patients who had undergone PCI, a follow-up strategy of routine functional testing, as compared with standard care alone, did not improve clinical outcomes at 2 years. (Funded by the CardioVascular Research Foundation and Daewoong Pharmaceutical; POST-PCI ClinicalTrials.gov number, NCT03217877.).

Prognostic Impact of Left Atrial Strain After Mitral Valve Repair Surgery in Patients With Severe Mitral Regurgitation.

BACKGROUND AND OBJECTIVES: The prognostic value of left atrial (LA) function in terms of long-term clinical outcomes after mitral regurgitation (MR) surgery remains unclear. Therefore, we investigated the impact of preoperative LA global longitudinal strain (LAGLS) on the long-term postoperative clinical outcomes in chronic severe MR patients who underwent mitral valve (MV) repair surgery. METHODS: From January 2012 to December 2017, we analyzed 338 patients (mean age, 51.9±12.5 years; 218 males [64.5%]) treated with MV repair surgery for severe MR. The primary outcome was cardiovascular events, defined as the composite of all-cause death, newly developed atrial fibrillation (AF), and re-hospitalization for cardiovascular causes. RESULTS: During a median follow-up of 45 months (interquartile range, 26-65), 30 (8.9%) cardiovascular events, 5 (1.5%) all-cause death, 8 (2.4%) newly developed AF, and 26 (7.7%) re-hospitalizations occurred. On multivariable analysis, baseline LAGLS was an independent predictor of cardiovascular events (adjusted hazard ratio [HR], 0.91; 95% confidential interval [CI], 0.85-0.97; p=0.004) and re-hospitalization (adjusted HR, 0.93; 95% CI, 0.86-1.00; p=0.037). According to the optimal cutoff value of LAGLS, patients with low LAGLS (<23.6%) had a significantly higher risk of cardiovascular events (adjusted HR, 2.70; 95% CI, 1.04-7.00; p=0.041) than those with high LAGLS (≥23.6%). In a subgroup analysis, patients with high LAGLS had better clinical outcomes regardless of whether the patient had a LA volume index <60 mL/m². CONCLUSIONS: In patients with chronic severe MR who received successful MV repair surgery, preoperative LAGLS is an independent predictor of long-term postoperative outcomes.

Time-Dependent Impact of Sex on the Long-Term Outcomes After Left Main Revascularization.

Background There are still limited data about the differential effect of sex on long-term outcomes after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for left main coronary artery disease. This extended follow-up study of the MAIN-COMPARE (Ten-Year Outcomes of Stents Versus Coronary-Artery Bypass Grafting for Left Main Coronary Artery Disease) registry evaluated clinical outcomes beyond 10 years. Methods and Results Of 2240 patients with unprotected left main coronary artery disease (PCI=1102 and CABG=1138), all-cause mortality, the composite of death, Q-wave myocardial infarction, or stroke, and target vessel revascularization were separately evaluated in both sexes. Of 2240 patients, 631 (28.2%) were women and 1609 (71.8%) were men. Women had lower 10-year incidences of death and serious composite outcomes than men. The adjusted 10-year risks of adverse outcomes were similar in men. However, the adjusted 10-year risks were different according to a prespecified period in women. In the short-term (0-1 year) period, PCI had a significantly lower risk for serious composite outcomes (adjusted hazard ratio [HR], 0.41; 95% CI, 0.19-0.91; P=0.03) compared with CABG. The adjusted risks for death and serious composite outcomes were significantly higher after PCI than after CABG, during the midterm (1-5 years) period (death; adjusted HR, 3.99; 95% CI, 2.01-7.92; P<0.001 and composite outcome; adjusted HR, 2.93; 95% CI, 1.59-5.39; P=0.001). Beyond 5 years, adjusted risks were similar after PCI and CABG in women. Conclusions In this 10-year extended follow-up study of patients undergoing left main coronary artery revascularization, we observed a time-dependent impact of sex on the long-term outcomes after PCI and CABG, especially in women, with significant interactions. However, these results warrant confirmation on larger series of studies. Registration URl: https://www.clinicaltrials.gov; Unique identifier: NCT02791412.

Radial Plus Ipsilateral Femoral Approach is Feasible in Percutaneous Interventions for Iliac Artery Chronic Total Occlusion.

BACKGROUND: Compared with conventional bilateral femoral (BF) approach, radial plus ipsilateral femoral (RF) approach may be feasible in the percutaneous intervention for iliac artery chronic total occlusion (CTO). METHODS: We included patients who underwent iliac CTO intervention between August 2009 and July 2018 in a tertiary referral center in Korea. RESULTS: A total of 83 patients were enrolled in this study. Of them, 51 and 32 patients were categorized into RF and BF initial access groups, respectively. The overall success rates were 98.0% and 96.7% in RF and BF group, respectively, and the techniques were also similar including use of bilateral wiring, stent type and profile, and post balloon but longer procedure time in the BF group. Additional contralateral femoral access was needed in 6 patients for the treatment of contralateral lesions, distal embolization, and due to tortuous right subclavian artery. Periprocedural complications including vascular injury, iliac perforation, and distal embolization occurred similarly in both groups with numerically lower rate of periprocedural bleeding in the RF group (9.8%) than in the BF group (21.9%). Clinical follow-up at 6 months showed there were no difference in the rates of death, cardiovascular death, target-limb reintervention, and unplanned target limb amputation in both groups. CONCLUSIONS: RF approach for iliac CTO intervention was related to similar technical success rate with acceptable periprocedural safety outcomes compared with conventional BF approach.

Pragmatic trial comparing routine versus no routine functional testing in high-risk patients who underwent percutaneous coronary intervention: Rationale and design of POST-PCI trial.

BACKGROUND: Although the need to detect restenosis has diminished in the contemporary practice of percutaneous coronary intervention (PCI) with drug-eluting stents (DES), the surveillance of ischemia owing to restenosis or disease progression deserves attention in high-risk PCI settings. It is unknown whether follow-up strategy of routine noninvasive functional testing potentially reduces the risk of major cardiovascular events in high-risk PCI patients. METHODS: The POST-PCI study is an investigator-initiated, multicenter, prospective randomized trial comparing the effectiveness of two follow-up strategies in patients with high-risk anatomic or clinical characteristics who underwent PCI. Study participants were randomly assigned to either (1) the routine noninvasive stress testing (exercise electrocardiography, nuclear stress imaging, or stress echocardiography) at 12 months post-PCI or (2) the standard-care without routine testing. In the routine stress testing group, depending on the testing results, all clinical decisions regarding subsequent diagnostic or therapeutic procedures were at the treating physician's discretion. The primary endpoint was a composite outcome of death from any causes, myocardial infarction, or hospitalization for unstable angina at 2 years post-PCI. RESULTS: More than 1700 high-risk PCI patients have been randomized over 2.0 years at 11 major cardiac centers in Korea. CONCLUSION: This pragmatic POST-PCI trial will provide valuable clinical evidence on the effectiveness of follow-up strategy of routine noninvasive stress testing in high-risk PCI patients.

Long-Term (10-Year) Outcomes of Stenting or Bypass Surgery for Left Main Coronary Artery Disease in Patients With and Without Diabetes Mellitus.

Background Data are still limited regarding whether there are differential long-term outcomes after percutaneous coronary intervention versus coronary artery bypass grafting (CABG) for left main coronary artery disease with or without diabetes mellitus (DM). Methods and Results Using the 10-year data from the MAIN-COMPARE (Revascularization for Unprotected Left Main Coronary Artery Stenosis: Comparison of Percutaneous Coronary Angioplasty Versus Surgical Revascularization) registry, we sought to examine the effect of DM on comparative outcomes after percutaneous coronary intervention or CABG in patients with unprotected left main coronary artery disease. The outcomes of interest were all-cause mortality; a composite of death, Q-wave myocardial infarction, or stroke; and target-vessel revascularization. The primary adjusted analyses were performed with the use of propensity scores and inverse-probability weighting. Of 2240 patients with left main coronary artery revascularization, 722 (32%) had DM. In the overall population, the adjusted 10-year risks of death and composite outcome were similar between percutaneous coronary intervention and CABG, irrespective of DM status (Pinteraction: 0.41, mortality; 0.40, composite outcome). However, in the cohort of bare-metal stents and concurrent CABG, we observed differential outcomes after stenting and CABG by DM status (Pinteraction: 0.09, mortality; 0.04, composite outcome), favoring CABG in patients with DM. In the cohort of drug-eluting stents and concurrent CABG, the better effect of CABG over stenting was narrowed in patients with DM without a significant interaction (Pinteraction: 0.63, mortality; 0.47, composite outcome). Conclusions In this cohort of patients with longest follow-up who underwent left main coronary artery revascularization, the clinical impact of DM favoring CABG over percutaneous coronary intervention has diminished over time from the bare-metal stent to the drug-eluting stent era. Registration URL: http://www.clini​caltr​ials.gov. Unique identifier: NCT02791412.

Impact of SYNTAX Score on 10-Year Outcomes After Revascularization for Left Main Coronary Artery Disease.

OBJECTIVES: The aim of this study was to investigate the long-term impact of SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score (SS) on differential outcomes after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for left main coronary artery (LMCA) disease. BACKGROUND: The very long term prognostic effect of SS on mortality and major cardiovascular events after LMCA revascularization is still undetermined. METHODS: In the MAIN-COMPARE (Ten-Year Outcomes of Stents Versus Coronary-Artery Bypass Grafting for Left Main Coronary Artery Disease) registry, patients with baseline SS measurements were analyzed. The 10-year rates of all-cause mortality, the composite of death, Q-wave myocardial infarction, or stroke, and target vessel revascularization after PCI or CABG were compared according to baseline SS. RESULTS: Among 1,580 patients with baseline SS, 547 patients (34.6%) had low SS (≤22), 350 (22.2%) had intermediate SS (23 to 32), and 683 (43.2%) had high SS (≥33). In patients with low to intermediate SS, the adjusted 10-year risks for death and serious composite outcome were similar between the PCI group and the CABG group. However, in patients with high SS, PCI with stenting, compared with CABG, was associated with a higher risk for death (hazard ratio: 1.39; 95% confidence interval: 1.00 to 1.92; p = 0.048) and serious composite outcome (hazard ratio: 1.27; 95% confidence interval: 0.94 to 1.74; p = 0.123). In each revascularization group, conventional tertiles of SS had a differential prognostic impact on 10-year clinical outcomes in the PCI arm but not in the CABG arm. CONCLUSIONS: In this 10-year extended follow-up of patients undergoing LMCA revascularization, CABG showed a clear prognostic benefit over PCI in patients with high anatomic complexity measured by SS at baseline. The discriminative capacity of SS on long-term outcomes was relevant in the PCI group but not in the CABG group. (Ten-Year Outcomes of Stents Versus Coronary-Artery Bypass Grafting for Left Main Coronary Artery Disease [MAIN-COMPARE]; NCT02791412).

Long-term (10-year) outcomes of stenting or bypass surgery for acute coronary syndromes and stable ischemic heart disease with unprotected left main coronary artery disease.

BACKGROUND: Acuity of clinical presentation may influence decision making of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for left main coronary artery (LMCA) disease. However, it is undetermined whether clinical indication for myocardial revascularization may affect the relative long-term effect after PCI and CABG. METHODS: In the MAIN-COMPARE study including 2,240 patients with LMCA disease treated with PCI (n = 1102) or CABG (n = 1138), we examined interaction between acuity of clinical presentation (acute coronary syndromes [ACS] or non-ACS) and revascularization strategy on 10-year outcomes. Primary outcome was a composite of all-cause death, Q-wave myocardial infarction, or stroke. Secondary outcomes were all-cause death or target vessel revascularization. RESULTS: In overall patients, 1,603 patients (71.6%) presented with ACS and 637 patients (28.4%) presented with non-ACS. The 10-year adjusted risks for primary composite outcome were similar after PCI and CABG among patients who presented with non-ACS (hazard ratio [HR] 1.07; 95% CI 0.71-1.61) and those who presented with ACS (HR 1.00; 95% CI 0.81-1.24) (P for interaction = .29). The adjusted risks of death were also similar between 2 groups in non-ACS (HR 0.98; 95% CI 0.63-1.51) and ACS (HR 1.02; 95% CI 0.81-1.28) patients (P for interaction = .62). The adjusted risks of target vessel revascularization were consistently higher after PCI in non-ACS (HR 6.38; 95% CI 3.14-12.96) and ACS (HR 3.96; 95% CI 2.80-5.60) patients (P for interaction = .39). CONCLUSIONS: In patients with LMCA disease, we have identified no significant interaction between the acuity of clinical indication and the relative treatment effect of PCI versus CABG on 10-year clinical outcomes.

The Mechanism of Hip Dislocation Related to the Use of Abduction Bar and Hip Compression Bandage in Patients With Spastic Cerebral Palsy.

OBJECTIVE: The aims of the study were to identify the differences of forces in the hip adductors between with or without the abduction bar and to evaluate the effect of hip compression bandage on the spasticity of the adductor muscles. DESIGN: Thirty-three patients with cerebral palsy (Gross Motor Functional Classification System IV and V) were prospectively included. Surface electromyography was taken by attaching electromyography on the adductor and abductor muscles. Theraband was used as hip compression bandage. Surface electromyography were taken when spasticity provoked with and without abduction bar, as well as with both abduction bar and hip compression bandage. Root mean square values were measured. RESULTS: Root mean square values were significantly increased with abduction bar in the adductor longus, adductor magnus, and tensor fascia lata muscles. Adductor Sum and Net Adduction Index showed significant increases after the use of abduction bar. After applying hip compression bandage, the Net Adduction Index was significantly decreased. CONCLUSIONS: Our results showed significant changes in the adductor muscles' amplitude, Adduction Sum, and Net Adduction Index. These results indicate that forces that worsen hip dislocation may develop, and therefore, abduction bar should either not be used for spastic cerebral palsy patients or should only be used with hip compression wrapping in place as well.

Effect of Age and Sex on Outcomes After Stenting or Bypass Surgery in Left Main Coronary Artery Disease.

Age and sex contribute to determining coronary revascularization strategies for patients with left main coronary artery (LMCA) disease. We examined age- and sex-related differences in comparative outcomes after percutaneous coronary intervention (PCI) or coronary-artery bypass grafting (CABG) for LMCA disease. A total of 4,001 patients with LMCA disease (men, n = 3,100, women, n = 901) who underwent PCI (n = 2,615) or CABG (n = 1,386) from the Interventional Research Incorporation Society-Left MAIN Revascularization registry were analyzed. Patients were stratified into subgroups according to the tertiles of age (<60 years, 60 to 69 years, and ≥70 years) and sex. The primary outcome was the composite of death from any cause, myocardial infarction, or stroke. During the median 6.3 years of follow-up, the adjusted risks for primary outcome after PCI relative to CABG were similar in patients aged <60 years (hazard ratio [HR]: 0.64, 95% confidence interval [CI]: 0.35 to 1.16), 60 to 69 years (HR: 1.21; 95% CI: 0.82 to 1.80), and ≥70 years (HR: 0.90; 95% CI: 0.66 to 1.22) with no significant age-related interactions (Pinteraction = 0.57). The primary outcome risks following PCI versus CABG were similar between male (HR: 0.92; 95% CI: 0.72 to 1.17) and female (HR: 0.89; 95% CI: 0.52 to 1.50) (Pinteraction = 0.65). Significant interactions were absent for age or sex and revascularization type for all-cause mortality (Pinteraction = 0.34 for age and Pinteraction = 0.99 for sex), repeat revascularization (Pinteraction = 0.10 for age and Pinteraction = 0.65 for sex), and major adverse cardiac or cerebrovascular events (Pinteraction = 0.29 for age and Pinteraction = 0.30 for sex). In conclusion, there were no significant age- or sex-related differences in comparative outcomes after PCI or CABG for LMCA disease.

Long-term trends of treatment effect of stenting or bypass surgery in patients with ostial or shaft left main coronary artery disease.

BACKGROUND: Little is known about how the relative treatment effect of percutaneous coronary intervention (PCI) and coronary-artery bypass grafting (CABG) on clinical outcomes in ostial or shaft left main coronary artery (LMCA) disease has evolved over time. METHODS: This study included 2,112 patients with ostial or shaft LMCA disease from IRIS-MAIN registry who underwent PCI (n = 1,329) or CABG (n = 783). Patients were stratified by time period based on stent type availability: wave 1 (1995-2002, bare-metal stent [BMS] era); wave 2 (2003-2006, first-generation drug-eluting stent [DES] era); and wave 3 (2007-2014, second-generation DES era). RESULTS: Compared to CABG, PCI has been used more frequently from wave 1 to wave 3. PCI showed substantial improvements over time with respect to death (P for trend = 0.012); the composite of death, myocardial infarction (MI), or stroke (P for trend = 0.047); repeat revascularization (P for trend < 0.001); and major adverse cardiac and cerebrovascular events (MACCE; a composite of death, MI, stroke, or repeat revascularization) (P for trend < 0.001). By contrast, outcomes of CABG remained relatively stable over time. The gap between the treatment effects of CABG vs PCI for MACCE has narrowed over time; the adjusted hazard ratios for CABG compared to PCI during wave 1, 2, and 3 were 0.41 (95% confidence interval [CI]: 0.22-0.76), 0.47 (95% CI: 0.31-0.71), and 0.78 (95% CI: 0.50-1.20), respectively. CONCLUSIONS: In patients with ostial or shaft LMCA disease, significant improvements in PCI outcomes resulted in a progressive decline in the gap between the outcomes of CABG and PCI.

10-Year Outcomes of Stents Versus Coronary Artery Bypass Grafting for Left Main Coronary Artery Disease.

BACKGROUND: Comparative outcomes of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) for left main coronary artery (LMCA) disease were previously reported. However, data on very long-term (>10 years) outcomes are limited. OBJECTIVES: The authors compare 10-year outcomes after PCI and CABG for LMCA disease. METHODS: In this observational study of the MAIN-COMPARE (Revascularization for Unprotected Left Main Coronary Artery Stenosis: Comparison of Percutaneous Coronary Angioplasty versus Surgical Revascularization) registry, the authors evaluated 2,240 patients with unprotected LMCA disease who underwent PCI (n = 1,102) or underwent CABG (n = 1,138) between January 2000 and June 2006. Adverse outcomes (death; a composite outcome of death, Q-wave myocardial infarction, or stroke; and target-vessel revascularization) were compared with the use of propensity scores and inverse-probability-weighting adjustment. The follow-up was extended to at least 10 years of all patients (median 12.0 years). RESULTS: In the overall cohort, there was no significant difference in adjusted risks of death and the composite outcome between the groups up to 10 years. The risk of target-vessel revascularization was significantly higher in the PCI group. In the cohort comparing drug-eluting stents and concurrent CABG, the 2 study groups did not differ significantly in the risks of death and the composite outcome at 5 years. However, after 5 years, drug-eluting stents were associated with higher risks of death (hazard ratio: 1.35; 95% confidence interval: 1.00 to 1.81) and the composite outcome (hazard ratio: 1.46; 95% confidence interval: 1.10 to 1.94) compared with CABG. CONCLUSIONS: In patients with significant LMCA disease, as compared with CABG, PCI showed similar rates of death and serious composite outcomes, but a higher rate of target-vessel revascularization at 10 years. However, CABG showed lower mortality and serious composite outcome rates compared with PCI with drug-eluting stents after 5 years. (Revascularization for Unprotected Left Main Coronary Artery Stenosis: Comparison of Percutaneous Coronary Angioplasty versus Surgical Revascularization [MAIN-COMPARE]; NCT02791412).

Transcatheter closures for fistula tract and paravalvular leak after mitral valve replacement and tricuspid annuloplasty.

Paravalvular leaks (PVLs) often occur after surgical valve replacement. Surgical reoperation has been the gold standard of therapy for PVLs, but it carries a higher operative risk and an increased incidence of re-leaks compared to the initial surgery. In high surgical risk patients with appropriate geometries, transcatheter closure of PVLs could be an alternative to redo-surgery. Here, we report a case of successful staged transcatheter closures of a fistula tract between the aorta and right atrium, and mitral PVLs after mitral valve replacement and tricuspid annuloplasty.

Lymphohematopoietic cancer mortality and morbidity of workers in a refinery/petrochemical complex in Korea.

OBJECTIVES: The purpose of this retrospective cohort study was to investigate the relationship between exposure of Korean workers to petrochemicals in the refinery/petrochemical industry and lymphohematopoietic cancers. METHODS: The cohort consisted of 8,866 male workers who had worked from the 1960s to 2007 at one refinery and six petrochemical companies located in a refinery/petrochemical complex in Korea that produce benzene or use benzene as a raw material. Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) were calculated for 1992-2007 and 1997-2005 based on the death rate and cancer incidence rate of the Korean male population according to job title (production, maintenance, laboratory, and office workers). RESULTS: The overall mortality and most cause-specific mortalities were lower among these workers than those of the general Korean population. Increased SMRs were observed for leukemia (4/1.45; SMR 2.77, 95% CI: 0.75-7.09) and lymphohematopoietic cancers (5/2.51; SMR 2, 95% CI: 0.65-4.66) in production workers, and increased SIRs were also observed in leukemia (3/1.34; SIR 2.24, 95% CI: 0.46-6.54) and lymphohematopoietic cancers (5/3.39; SIR 1.47, 95% CI: 0.48-3.44) in production workers, but the results were not statistically significant. CONCLUSION: The results showed a potential relationship between leukemia and lymphohematopoietic cancers and exposure to benzene in refinery/petrochemical complex workers. This study yielded limited results due to a short observational period; therefore, a follow-up study must be performed to elucidate the relationship between petrochemical exposure and cancer rates.