Ischemic Burden Assessment Using Single Photon Emission Computed Tomography in Single Vessel Chronic Total Occlusion of Coronary Artery

Background and Objectives@#Studies evaluating the nature of ischemic burden of chronic total occlusion (CTO) vessels are still lacking. @*Methods@#A total of 165 patients with single vessel CTO >2.5 mm in an epicardial coronary artery who underwent single photon emission computed tomography (SPECT) were enrolled in the study. Ischemic burden was calculated with the use of semi-quantitative SPECT analysis, and was defined as the summed difference score (SDS) divided by the maximal limit of the score (=SDS/68). @*Results@#The mean age of the participants was 59.5 years and the CTO of the left anterior descending coronary artery (LAD), left circumplex coronary artery (LCX), and right coronary artery (RCA) accounted for 93 (56.4%), 18 (10.9%), and 54 (32.7%) patients, respectively. The median ischemic burden of the total population was 8.8%, and it was highest in the LAD CTO (10.3%) compared with the LCX (5.9%) and RCA CTO (5.9%, p10%) was observed in 66 patients (40.0%), and in 47 patients (50.5%) of the LAD CTO. Ischemic burden was different according to the CTO location only in LAD CTO. The statistically significant predictors for high-ischemic burden were hypertension, baseline ejection fraction >45%, LAD CTO, proximal CTO location, and de novo CTO. Japanese-CTO score and Rentrop scale collateral grade were not associated with high-ischemic burden. @*Conclusions@#Only 40% of patients with single vessel CTO had ischemic burden >10%. For CTO vessels, measurement of ischemic burden using SPECT prior to revascularization may be helpful in identifying beneficial subjects.

Long-Term Clinical Outcomes of Iliac Artery Endovascular Therapy in the Korean Vascular Intervention Society Endovascular Therapy in Lower Limb Artery Diseases (K-VIS ELLA) Registry

Background and Objectives@#Limited data are available regarding long-term clinical outcomes of iliac artery endovascular therapy (EVT) in real-world practice. This study investigated long-term outcomes according to Trans-Atlantic Inter-Society Consensus (TASC) classifications. @*Methods@#We analyzed data from 1,705 limbs of 1,364 patients from the retrospective cohort of the multicenter Korean Vascular Intervention Society Endovascular Therapy in Lower Limb Artery Disease registry. The primary endpoint was target lesion revascularization (TLR)-free survival. @*Results@#TASC A, B, C, and D lesions were present in 19.4%, 26.2%, 28.7%, and 25.7% of the treated limbs, respectively. The technical success rate was 96.2% and did not differ between TASC lesion types. Complications occurred in 6.8% of cases and more occurred in TASC D (11.8%). Iliac artery EVT showed a 5-year TLR-free survival of 89.2%. The TASC D group had the lowest TLR-free rate of 79.3%. TASC D (hazard ratio [HR], 1.75; 95% confidence interval [CI], 1.12–2.73; p=0.014), plain old balloon angioplasty (HR, 4.25; 95% CI, 2.03–8.88; p<0.001), current smoker (HR, 1.89; 95% CI, 1.26–2.83; p=0.002), previous bypass surgery (HR, 3.04;95% CI, 1.28–7.19; p=0.011), combined femoropopliteal treatment (HR, 4.89; 95% CI, 3.19–7.50; p<0.001), combined below the knee treatment (HR, 2.20; 95% CI, 1.25–3.89; p=0.007), and complications (HR, 1.86; 95% CI, 1.07–3.24; p=0.028) were predictors for TLR. @*Conclusions@#Iliac artery EVT achieved excellent technical success and 5-year TLR-free survival. TASC D showed a favorable but lower 5-year TLR-free survival rate and higher complication rate compared with other TASC groups.

Long-term Clinical Outcomes and Prognostic Factors After Endovascular Treatment in Patients With Chronic Limb Threatening Ischemia

Background and Objectives@#Endovascular therapy (EVT) first strategy has been widely adopted for the treatment of chronic limb threatening ischemia (CLTI) patients in realworld practice. This study aimed to investigate long-term outcomes of CLTI patients who underwent EVT and identify prognostic factors. @*Methods@#From the retrospective cohorts of a Korean multicenter endovascular therapy registry, 1,036 patients with CLTI (792 men, 68.8 ± 9.5 years) were included. The primary endpoint was amputation-free survival (AFS) defined as the absence of major amputation or death. Secondary endpoints were major adverse limb events (MALE; a composite of major amputation, minor amputation, and reintervention). @*Results@#Five-year AFS and freedom from MALE were 69.8% and 61%, respectively. After multivariate analysis, age (hazard ratio [HR], 1.476; p<0.001), end-stage renal disease (ESRD; HR, 2.340; p<0.001), Rutherford category (RC) 6 (HR, 1.456; p=0.036), and suboptimal EVT (HR, 1.798; p=0.005) were identified as predictors of major amputation or death, whereas smoking (HR, 0.594; p=0.007) was protective. Low body mass index (HR, 1.505; p=0.046), ESRD (HR, 1.648; p=0.001), femoropopliteal lesion (HR, 1.877; p=0.004), RC-6 (HR, 1.471;p=0.008), and suboptimal EVT (HR, 1.847; p=0.001) were predictors of MALE. The highest hazard rates were observed during the first 6 months for both major amputation or death and MALE. After that, the hazard rate decreased and rose again after 3–4 years. @*Conclusions@#In CLTI patients, long-term outcomes of EVT were acceptable. ESRD, RC-6, and suboptimal EVT were common predictors for poor clinical outcomes.

Association between Body Mass Index and Clinical Outcomes of Peripheral Artery Disease after Endovascular Therapy: Data from K-VIS ELLA Registry

Background and Objectives@#Few studies have investigated the obesity paradox in clinical outcomes of peripheral artery disease (PAD). We investigated the association between body massindex (BMI) and clinical outcomes in PAD patients undergoing endovascular therapy (EVT). @*Methods@#Patients (n=2,914) from the retrospective Korean Vascular Intervention Society Endovascular Therapy in Lower Limb Artery Disease registry were categorized according to BMI: underweight (<18.5 kg/m2 , n=204), normal weight (18.5–25 kg/m2 , n=1,818), overweight (25–30 kg/m2 , n=766), or obese (≥30 kg/m2 , n=126). Groups were compared for major adverse cardiovascular events (MACE) and major adverse limb events (MALE). @*Results@#The underweight and obese groups were older and had more frequent critical limb ischemia and infrapopliteal artery disease than the normal or overweight groups (all p<0.001). Hypertension and diabetes were more frequent and current smoking was less frequent in the overweight and obese groups than the underweight or normal weight groups (all p <0.001). The underweight group showed the higher rates of MACE and MALE at 3 years (17.2%, 15.7%) compared with the normal weight (10.8%, 11.7%), overweight (8.4%, 10.7%), or obese groups (8.7%, 14.3%) (log-rank p<0.001, p=0.015). In contrast, the risk of MACE was lower in the overweight than the normal weight group (adjusted hazard ratio, 0.706; 95% CI, 0.537–0.928). @*Conclusions@#In PAD patients undergoing EVT, underweight was an independent predictor for MACE and MALE, whereas MACE risk was lower for overweight than normal weight patients.

Association between Body Mass Index and Clinical Outcomes of Peripheral Artery Disease after Endovascular Therapy: Data from K-VIS ELLA Registry

Background and Objectives@#Few studies have investigated the obesity paradox in clinical outcomes of peripheral artery disease (PAD). We investigated the association between body massindex (BMI) and clinical outcomes in PAD patients undergoing endovascular therapy (EVT). @*Methods@#Patients (n=2,914) from the retrospective Korean Vascular Intervention Society Endovascular Therapy in Lower Limb Artery Disease registry were categorized according to BMI: underweight (<18.5 kg/m2 , n=204), normal weight (18.5–25 kg/m2 , n=1,818), overweight (25–30 kg/m2 , n=766), or obese (≥30 kg/m2 , n=126). Groups were compared for major adverse cardiovascular events (MACE) and major adverse limb events (MALE). @*Results@#The underweight and obese groups were older and had more frequent critical limb ischemia and infrapopliteal artery disease than the normal or overweight groups (all p<0.001). Hypertension and diabetes were more frequent and current smoking was less frequent in the overweight and obese groups than the underweight or normal weight groups (all p <0.001). The underweight group showed the higher rates of MACE and MALE at 3 years (17.2%, 15.7%) compared with the normal weight (10.8%, 11.7%), overweight (8.4%, 10.7%), or obese groups (8.7%, 14.3%) (log-rank p<0.001, p=0.015). In contrast, the risk of MACE was lower in the overweight than the normal weight group (adjusted hazard ratio, 0.706; 95% CI, 0.537–0.928). @*Conclusions@#In PAD patients undergoing EVT, underweight was an independent predictor for MACE and MALE, whereas MACE risk was lower for overweight than normal weight patients.

Impact of Diabetes Control on Subclinical Atherosclerosis: Analysis from Coronary Computed Tomographic Angiography Registry

Background@#There are limited data on the impact of diabetes control on the risk of subclinical coronary atherosclerosis. @*Methods@#We analyzed 6,434 consecutive asymptomatic individuals without previous history of coronary artery disease who underwent coronary computed tomographic angiography (CCTA) (mean age, 53.7±7.6 years and 4,694 men [73.0%]). The degree and extent of subclinical coronary atherosclerosis were assessed by CCTA, and ≥50% diameter stenosis was defined as significant. A cardiac event was defined as a composite of all-cause death, myocardial infarction, unstable angina, or coronary revascularization. Study participants were categorized as normal (n=5,319), controlled diabetes (glycosylated hemoglobin [HbA1c] <7%, n=747), or uncontrolled diabetes (HbA1c ≥7%, n=368), respectively. @*Results@#Compared with normal individuals, there were no statistically significant differences in the risk of for any atherosclerotic plaque (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.98 to 1.38; p=0.086) and significant coronary artery stenosis (OR, 1.08; 95% CI, 0.82 to 1.42; p=0.583) in controlled diabetic individuals. In contrast, uncontrolled diabetic individuals had consistently higher risks of any atherosclerotic plaque (OR, 2.16; 95% CI, 1.70 to 2.75; p<0.001) and significant coronary artery stenosis (OR, 3.34; 95% CI, 2.52 to 4.43; p<0.001) than normal individuals. During a follow-up of median 5.4 years, there was no significant difference in cardiac events between normal and controlled diabetic individuals (p=0.365). However, uncontrolled diabetes was associated with an increased risk of cardiac events compared with normal individuals (P<0.001) and controlled diabetic individuals (p=0.023). @*Conclusion@#Asymptomatic uncontrolled diabetes was associated with significant subclinical coronary atherosclerosis with subsequent high risk for cardiac events.

Differential efficacy between stenting and plain balloon angioplasty for femoropopliteal disease with or without total occlusion

Background/Aims@#Whether the presence of chronic total occlusion (CTO) affects patency after stenting in femoropopliteal lesions is unknown. We determined the effects of plain balloon angioplasty (POBA) in comparison with those of stenting on patency for femoropopliteal CTO and stenosis (non-CTO). @*Methods@#We analyzed data from the Korean Vascular Intervention Society Endovascular Therapy in Lower-Limb Artery Diseases Registry, a multicenter cohort of patients with lower extremity peripheral arterial disease. Data from 1,329 patients and 1558 limbs treated with endovascular intervention for at least one femoropopliteal lesion were evaluated. @*Results@#Among the 1,558 limbs, 345, 432, 275, and 506 were in the non-CTO-POBA,non-CTO-stent, CTO-POBA, and CTO-stent groups, respectively. During follow-up, loss of clinical primary patency, a composite of freedom from restenosis or clinically driven target lesion revascularization, occurred in 65 (18.8%), 68 (15.7%), 62 (22.5%), and 113 limbs (22.3%) in the non-CTO-POBA, non-CTO-stent, CTO-POBA, and CTO-stent groups, respectively. The patients in the non-CTOstent group showed a significantly better clinical primary patency than those in the no-CTO-POBA group, whereas those in the CTO-stent and CTO-POBAgroups showed no significant differences. After inverse probability of treatment weighting to balance the differences among covariates between the non-CTOstent and non-CTO-POBA groups, the non-CTO-stent group still showed superior clinical primary patency as compared with the non-CTO-POBA group. @*Conclusions@#In the patients with femoropopliteal stenosis without CTO, stenting resulted in better clinical outcomes than balloon angioplasty. The presence of CTO in the femoropopliteal lesion should be considered when selecting a suitable device for performing endovascular procedures.

Unexpected Stenosis within Significantly Enlarged Distal Vessel after Successful Coronary Chronic Total Occlusion Recanalization

No abstract available.

Stent Selection in Complex Coronary Interventions: Thinking Complex?

No abstract available.

Assessment of Tissue Perfusion with Blood Oxygenation Level-Dependent Magnetic Resonance Imaging in Critical Limb Ischemia

No abstract available.

Trends, Characteristics, and Clinical Outcomes of Patients Undergoing Percutaneous Coronary Intervention in Korea between 2011 and 2015

BACKGROUND AND OBJECTIVES: We sought to evaluate nationwide trends, characteristics, and clinical outcomes in patients undergoing percutaneous coronary intervention (PCI) in Korea. METHODS: From National Health Insurance claims data in Korea, 81,115 patients, who underwent PCI for the first episode of coronary artery disease between 2011 and 2015, were enrolled. Patients were categorized into angina (n=49,288) or acute myocardial infarction (AMI, n=31,887) groups and analyzed. RESULTS: The mean age of patients was 64.4±12.2 years and 56,576 (69.7%) were men. Diabetes, hyperlipidemia, and hypertension were observed in 27,086 (33.4%), 30,675 (37.8%), and 45,389 (56.0%) patients, respectively. There was a 10% increase in the number of patients undergoing PCI for angina between 2011–2012 and 2014–2015 (11,105 vs. 13,261; p=0.021). However, the number of patients undergoing PCI for AMI marginally decreased between 2011–2012 and 2014–2015 (8,068 vs. 7,823; p=0.052). In procedures, drug-eluting stent was the most frequently used device (93.2%), followed by balloon angioplasty (5.5%) and bare metal stents (1.3%). The mean number of stents per patient was 1.39±0.64. At discharge, dual-anti platelet therapy, statin, beta-blockers, and angiotensin converting enzyme inhibitor or angiotensin receptor blocker were provided to 76,292 (94.1%), 71,411 (88.0%), 57,429 (70.8%), and 54,418 (67.1%) patients, respectively. The mean in-hospital and 1-year total medical costs were 8,628,768±4,832,075 and 13,128,158±9,758,753 Korean Won, respectively. In-hospital mortality occurred in 2,094 patients (2.6%). CONCLUSIONS: Appropriate healthcare strategies reflecting trends, characteristics, and clinical outcomes of PCI are needed in Korea.

Diabetes and Subclinical Coronary Atherosclerosis

It is well known that diabetic patients have a high risk of cardiovascular events, and although there has been a tremendous effort to reduce these cardiovascular risks, the incidence of cardiovascular morbidity and mortality in diabetic patients remains high. Therefore, the early detection of coronary artery disease (CAD) is necessary in those diabetic patients who are at risk of cardiovascular events. Significant medical and radiological advancements, including coronary computed tomography angiography (CCTA), mean that it is now possible to investigate the characteristics of plaques, instead of solely evaluating the calcium level of the coronary artery. Recently, several studies reported that the prevalence of subclinical coronary atherosclerosis (SCA) is higher than expected, and this could impact on CAD progression in asymptomatic diabetic patients. In addition, several reports suggest the potential benefit of using CCTA for screening for SCA in asymptomatic diabetic patients, which might dramatically decrease the incidence of cardiovascular events. For these reasons, the medical interest in SCA in diabetic patients is increasing. In this article, we sought to review the results of studies on CAD in asymptomatic diabetic patients and discuss the clinical significance and possibility of using CCTA to screen for SCA.

Early experience and favorable clinical outcomes of everolimus-eluting bioresorbable scaffolds for coronary artery disease in Korea

BACKGROUND/AIMS: Compared with metallic drug-eluting stents (DES), bioresorbable vascular scaffolds (BVS) may further improve long-term outcomes of percutaneous coronary intervention (PCI) in patients with coronary artery disease. We report our early experience with BVS in Korea. METHODS: We evaluated 105 consecutive patients with BVS implanted at Asan Medical Center, Korea between October 21, 2015 and June 3, 2016. Angiographic results, and in-hospital and 6-month clinical outcomes were assessed. RESULTS: A total of 134 BVS were implanted to treat 115 lesions. The mean age was 62 ± 10.5 years; 85 patients (81%) were males, 26 patients (25%) were presented with acute coronary syndrome. Among 115 lesions treated with BVS, 76 (66.1%) were B2/C type, 27 (23.5%) were bifurcation lesions, and four (3.5%) were chronic total occlusion. Pre-dilation and post-dilation using high-pressure non-compliant balloon was performed in 104 lesions (90.4%) and 113 lesions (98.2%), respectively. During the procedure, intravascular imaging was used for all patients (100%; intravascular ultrasound 89 and optical coherence tomography 40 patients). Device success rate was 100%. In-segment and in-scaffold acute again were 1.1 ± 0.6 and 1.3 ± 0.5 mm, respectively. Periprocedural myocardial infraction occurred in four patients (3.8%). No deaths, stent thrombosis, or urgent revascularizations occurred either during hospitalization or the follow-up period. CONCLUSIONS: In this single-center experience, implantation of BVS with intravascular imaging support was feasible and early clinical outcomes were excellent. Evaluation of long-term efficacy and safety of BVS and its feasibility in clinical use for a broader range of lesions is warranted.

Trends, Characteristics, and Clinical Outcomes of Patients Undergoing Percutaneous Coronary Intervention in Korea between 2011 and 2015

BACKGROUND AND OBJECTIVES@#We sought to evaluate nationwide trends, characteristics, and clinical outcomes in patients undergoing percutaneous coronary intervention (PCI) in Korea.@*METHODS@#From National Health Insurance claims data in Korea, 81,115 patients, who underwent PCI for the first episode of coronary artery disease between 2011 and 2015, were enrolled. Patients were categorized into angina (n=49,288) or acute myocardial infarction (AMI, n=31,887) groups and analyzed.@*RESULTS@#The mean age of patients was 64.4±12.2 years and 56,576 (69.7%) were men. Diabetes, hyperlipidemia, and hypertension were observed in 27,086 (33.4%), 30,675 (37.8%), and 45,389 (56.0%) patients, respectively. There was a 10% increase in the number of patients undergoing PCI for angina between 2011–2012 and 2014–2015 (11,105 vs. 13,261; p=0.021). However, the number of patients undergoing PCI for AMI marginally decreased between 2011–2012 and 2014–2015 (8,068 vs. 7,823; p=0.052). In procedures, drug-eluting stent was the most frequently used device (93.2%), followed by balloon angioplasty (5.5%) and bare metal stents (1.3%). The mean number of stents per patient was 1.39±0.64. At discharge, dual-anti platelet therapy, statin, beta-blockers, and angiotensin converting enzyme inhibitor or angiotensin receptor blocker were provided to 76,292 (94.1%), 71,411 (88.0%), 57,429 (70.8%), and 54,418 (67.1%) patients, respectively. The mean in-hospital and 1-year total medical costs were 8,628,768±4,832,075 and 13,128,158±9,758,753 Korean Won, respectively. In-hospital mortality occurred in 2,094 patients (2.6%).@*CONCLUSIONS@#Appropriate healthcare strategies reflecting trends, characteristics, and clinical outcomes of PCI are needed in Korea.

Coronary Artery Bypass Grafting vs. Drug-Eluting Stent Implantation for Multivessel Disease in Patients with Chronic Kidney Disease

BACKGROUND AND OBJECTIVES: There is currently a limited amount of data that demonstrate the optimal revascularization strategy for chronic kidney disease (CKD) patients with multivessel coronary artery disease (CAD). We compared the long-term outcomes of percutaneous coronary intervention (PCI) with drug-eluting stents (DES) versus coronary artery bypass graft surgery (CABG) for multivessel CAD in patients with CKD. SUBJECTS AND METHODS: We analyzed 2108 CKD patients (estimated glomerular filtration rate <60 mL/min/1.73 m²) with multivessel CAD that were treated with PCI with DES (n=1165) or CABG (n=943). The primary outcome was a composite of all causes of mortality, myocardial infarction, or stroke. The mean age was 66.9±9.1 years. RESULTS: Median follow-up duration was 41.4 (interquartile range 12.1-75.5) months. The primary outcome occurred in 307 (26.4%) patients in the PCI group compared with 304 (32.2%) patients in the CABG group (adjusted hazard ratio [HR], 0.941; 95% confidence interval [CI], 0.79–1.12; p=0.493). The two groups exhibited similar rates of all-cause mortality (adjusted HR, 0.91; 95% CI, 0.77–1.09; p=0.295), myocardial infarction (adjusted HR, 1.86; 95% CI, 0.85–4.07; p=0.120) and stroke (3.2% vs. 4.8%; HR, 0.93; 95% CI, 0.57–1.61; p=0.758). However, PCI was associated with significantly increased rates of repeat revascularization (adjusted HR, 4.72; 95% CI, 3.20–6.96; p<0.001). CONCLUSION: Among patients with CKD and multivessel CAD, PCI with DES when compared with CABG resulted in similar rates of composite outcome of mortality from any cause, MI, or stroke; however, a higher risk of repeat revascularization was observed.

Baseline Characteristics of a Retrospective Patient Cohort in the Korean Vascular Intervention Society Endovascular Therapy in Lower Limb Artery Diseases (K-VIS ELLA) Registry

BACKGROUND AND OBJECTIVES: The Korean Vascular Intervention Society Endovascular Therapy in Lower Limb Artery Diseases (K-VIS ELLA) Registry is a multicenter observational study with retrospective and prospective cohorts of patients with lower extremity peripheral artery disease (PAD) undergoing endovascular treatment. In this study, we report the baseline characteristics of this retrospective cohort. SUBJECTS AND METHODS: In the present study we analyzed datasets of 3073 patients with 3972 target limbs from a retrospective cohort treated with endovascular therapy in 31 Korean hospitals. Data regarding patient baseline clinical and lesion characteristics and postintervention medications were collected from electronic medical records. RESULTS: The mean patient age was 68.3±9.4 years. The majority were male (82.1%) with comorbidities such as diabetes mellitus (58.0%), hypertension (73.4%), and coronary artery disease (CAD; 55.3%). Patients more commonly presented with intermittent claudication (66.3%) than with critical limb ischemia (CLI; 33.7%). Femoropopliteal artery (41.2%) was the most common target vessel for endovascular treatment, followed by the aortoiliac (35.6%) and infrapopliteal arteries (23.2%). TransAtlantic Inter-Society Consensus for the Management of Peripheral Artery Disease (TASC II) type C/D aortoiliac (48.0%) or femoropopliteal lesions (60.2%) were frequent targets of endovascular treatment. At hospital discharge, only 73.1% of patients received dual antiplatelet therapy and 69.2% received a statin. CONCLUSION: The majority of Korean patients with PAD exhibited conventional risk factors, such as male sex, older age, diabetes, and hypertension with coexisting CAD. Complex lesions were frequently treated with endovascular therapy. However, the rate of adherence to guidelines regarding post-procedural medical treatment requires improvement.

Impact of Follow-Up Ischemia on Myocardial Perfusion Single-Photon Emission Computed Tomography in Patients with Coronary Artery Disease

PURPOSE: Few studies have reported on predicting prognosis using myocardial perfusion single-photon emission computed tomography (SPECT) during coronary artery disease (CAD) treatment. Therefore, we aimed to assess the clinical implications of myocardial perfusion SPECT during follow-up for CAD treatment. MATERIALS AND METHODS: We enrolled 1153 patients who had abnormal results at index SPECT and underwent follow-up SPECT at intervals ≥6 months. Major adverse cardiac events (MACE) were compared in overall and 346 patient pairs after propensity-score (PS) matching. RESULTS: Abnormal SPECT was associated with a significantly higher risk of MACE in comparison with normal SPECT over the median of 6.3 years (32.3% vs. 19.8%; unadjusted p<0.001). After PS matching, abnormal SPECT posed a higher risk of MACE [32.1% vs. 19.1%; adjusted hazard ratio (HR)=1.73; 95% confidence interval (CI)=1.27–2.34; p<0.001] than normal SPECT. After PS matching, the risk of MACE was still higher in patients with abnormal follow-up SPECT in the revascularization group (30.2% vs. 17.9%; adjusted HR=1.73; 95% CI=1.15–2.59; p=0.008). Low ejection fraction [odds ratio (OR)=5.33; 95% CI=3.39–8.37; p<0.001] and medical treatment (OR=2.68; 95% CI=1.93–3.72; p<0.001) were independent clinical predictors of having an abnormal result on follow-up SPECT. CONCLUSION: Abnormal follow-up SPECT appears to be associated with a high risk of MACE during CAD treatment. Follow-up SPECT may play a potential role in identifying patients at high cardiovascular risk.

Monitoring the Antiplatelet Effect of Cilostazol with Light Transmission Aggregometer: Two Cases of Possible Cilostazol Resistance

BACKGROUND: Coronary artery disease is an important cause of death in adults and stent insertion is one of the treatment modalities. The most severe adverse effect of a stent insertion is the formation of a thrombus; therefore, antiplatelet agents are used. The addition of cilostazol to low-dose aspirin and clopidogrel results in a better antiplatelet effect. However, laboratory tests to monitor the effect of cilostazol are insufficient. METHODS: We tested the inhibitory effect of cilostazol using maximal platelet aggregation in 20 healthy volunteers. Conditions for incubation and concentrations of cilostazol and prostaglandin E1 (PGE1) were established and aggregation was induced by 5'-adenosine diphosphate (ADP) and measured with light transmission aggregometry (LTA). Blood samples were incubated with 1 µM and 2 µM cilostazol for 10 minutes at room temperature, and 80 nM PGE1 was added and incubated for an additional 10 minutes. Aggregation was induced by ADP and reactivity was evaluated. RESULTS: The average maximum aggregation (MA) was 58.1% at 1 µM cilostazol and 22.0% when PGE1 was added. The average MA was 42.8% when cilostazol concentration was increased to 2 µM and 21.2% when PGE1 was added. Average inhibition of aggregation at 1 µM cilostazol was not statistically significant (P=0.085), but was significant (P=0.004) at 2 µM cilostazol. Aggregation was not inhibited even with 2 µM cilostazol and PGE1 in 2 volunteers, which suggests possible resistance to cilostazol. CONCLUSIONS: We designed a method to monitor the effect of cilostazol using in vitro incubation with PGE1.

Role of Coronary Artery Calcium Scoring in Detection of Coronary Artery Disease according to Framingham Risk Score in Populations with Low to Intermediate Risks

Current guidelines recommend that coronary artery calcium (CAC) screening should only be used for intermediate risk groups (Framingham risk score [FRS] of 10%-20%). The CAC distributions and coronary artery disease (CAD) prevalence in various FRS strata were determined. The benefit to lower risk populations of CAC score-based screening was also assessed. In total, 1,854 participants (aged 40-79 years) without history of CAD, stroke, or diabetes were enrolled. CAC scores of > 0, ≥ 100, and ≥ 300 were present in 33.8%, 8.2%, and 2.9% of the participants, respectively. The CAC scores rose significantly as the FRS grew more severe (P 20% strata were 3.4%, 6.7%, 9.0%, and 11.6% (P 20%; P < 0.05). In conclusion, the yield of screening for significant CAC and occult CAD is low in the very low risk population but it rises in low and intermediate risk populations.

Two Cases of Immediate Stent Fracture after Zotarolimus-Eluting Stent Implantation

Drug-eluting stent (DES) implantation is currently the standard treatment for various types of coronary artery disease. However, previous reports indicate that stent fractures, which usually occur after a period of time from the initial DES implantation, have increased during the DES era; stent fractures can contribute to unfavorable events such as in-stent restenosis and stent thrombosis. In our present report, we describe two cases of zotarolimus-eluting stent fracture: one that was detected six hours after implementation, and the other case that was detected immediately after deployment. Both anatomical and technical risk factors contributed to these unusual cases of immediate stent fracture.