Byung-Hee Hwang

Impact of diabetes duration on the extent and severity of coronary atheroma burden and long-term clinical outcome in asymptomatic type 2 diabetic patients: evaluation by Coronary CT angiography

AIMS We investigated the association between diabetes duration and the extent and severity of coronary artery disease (CAD) as well as long-term clinical outcomes using coronary computed tomography angiography (CCTA) in asymptomatic type 2 diabetic patients. METHODS AND RESULTS We analysed 933 asymptomatic type 2 diabetic patients without known CAD who underwent CCTA. Patients were divided into three groups according to the duration of diabetes: <5 years, 5-10 years, and ≥10 years. Stenosis by CCTA was scored as none (0%), non-obstructive (1-49%), or obstructive (≥50%) for each coronary artery segment. For these patients, we compared the prevalence, extent, and severity of CAD, including coronary artery calcium score (CACS), atheroma burden obstructive score (ABOS), segment involvement score (SIS), and segment stenosis score (SSS). Major adverse cardiac and cerebrovascular events (MACCE), including all-cause mortality, non-fatal myocardial infarction, and stroke, within a follow-up period were also compared.Patients with longer duration of diabetes possessed higher rates of obstructive CAD (P < 0.001). Patients with longer duration of diabetes also manifested greater degree of CACS, ABOS, SIS, and SSS (P < 0.001 for all) with associated higher rate of MACCE (P = 0.025). Presence of obstructive CAD as assessed by CCTA was an independent predictor of MACCE after adjusting for confounding risk factors (hazard ratio: 1.979, confidence interval: 1.178-3.327, P = 0.010). CONCLUSION In asymptomatic diabetic patients, longer diabetes duration is associated with a higher prevalence, extent, and severity of CAD as well as risk of MACCE. Moreover, greater CAD burden increases the risk of MACCE independent of co-existing CAD risk factors.

Microalbuminuria is independently associated with arterial stiffness and vascular inflammation but not with carotid intima-media thickness in patients with newly diagnosed type 2 diabetes or essential hypertension.

The association between microalbuminuria (MAU) and the indices of macrovascular complication in patients with newly diagnosed type 2 diabetes (D) or essential hypertension (H) was evaluated. Total 446 patients were classified into four groups according to the urinary albumin-to-creatinine ratio: MAU-D (n = 104), normoalbuminuria (NAU)-D (n = 114), MAU-H (n = 116), and NAU-H (n = 112). The indices of macrovascular complication including arterial stiffness evaluated by pulse-wave-velocity (PWV), carotid intima-media thickness (IMT), and vascular inflammation marked by high-sensitivity C-reactive protein (hsCRP) were assessed. PWV, IMT, and hsCRP were higher in patients with MAU than in those with NAU in both diabetes and hypertension groups. In both MAU-D and MAU-H groups, PWV and hsCRP levels were positively correlated with MAU level (MAU-D: r = 0.47, 0.41, MAU-H: r = 0.36, 0.62, respectively, P < 0.05). Additionally, PWV and hsCRP were independent factors predicting MAU (diabetes group: OR 1.85, 1.54, hypertension group: OR 1.38, 1.51, respectively, P < 0.001), but not IMT. MAU is independently associated with arterial stiffness and vascular inflammation but not with IMT in patients with newly diagnosed type 2 diabetes or essential hypertension, which emphasizes the importance of proactive clinical investigations for atherosclerotic complications in patients with MAU, even in newly diagnosed diabetes or hypertension.

Impact of the Stent Length on Long-Term Clinical Outcomes Following Newer-Generation Drug-Eluting Stent Implantation

Stent length has been considered an important predictor of adverse events after percutaneous coronary intervention, even with the first-generation drug-eluting stents (DESs). The introduction of newer-generation DES has further reduced the rates of adverse clinical events such as restenosis, myocardial infarction, and stent thrombosis. The aim of this study was to compare the impact of stent length on the long-term clinical outcomes between first- and newer-generation DESs. The effects of stent length (≥32 vs <32 mm) on the clinical outcomes were evaluated in 8,445 patients who underwent percutaneous coronary intervention using either a first-generation DES (sirolimus- and paclitaxel-eluting stents, n = 6,334) or a newer-generation DES (everolimus- and zotarolimus-eluting stents, n = 2,111) from January 2004 to December 2009. The 3-year adverse outcomes (composite of all-cause death, nonfatal myocardial infarction, target vessel revascularization, and stent thrombosis) were compared using the inverse probability of treatment-weighted method according to the stent length. After adjustment for differences in the baseline risk factors, a stent length of ≥32 mm was significantly associated with higher cumulative rates of target vessel revascularization and stent thrombosis in the patients treated with a first-generation DES (adjusted hazard ratio 1.875, 95% confidence interval 1.531 to 2.297, p <0.001; adjusted hazard ratio 2.964, 95% confidence interval 1.270 to 6.917, p = 0.012), but it was not associated with the clinical outcomes in patients treated with a newer-generation DES. In conclusion, stent length might not be associated with long-term clinical outcomes in newer-generation DES era, whereas stent length might be associated with long-term clinical outcomes in the first-generation DESs.

Intestinal Helminthic Infections Diagnosed by Colonoscopy in a Regional Hospital during 2001-2008

The present study investigated characteristics of 24 parasite infection cases detected during colonoscopy in a regional hospital from January 2001 to December 2008. Sixteen patients were confirmed with Trichuris trichiura infection, 6 patients were with Ascaris lumbricoides infection, 1 patient with Enterobius vermicularis infection, and 1 patient with Anisakis infection. Among them, 7 patients (43.8%) were asymptomatic. Colonoscopy findings were normal in 18 patients (75.0%). Among the patients with T. trichiura infection, colonoscopy showed several erosions in 2 patients (8.3%) and non-specific inflammation of the affected segment of the colon in 3 patients (12.5%). In 1 patient with anisakiasis, colonoscopy revealed a markedly swollen colonic wall. Stool examinations were performed before treatment in 7 patients (29.2%) and were all negative for parasite eggs or worms. These results suggest that colonoscopy is a useful diagnostic approach for parasitic infections even for asymptomatic patients and for patients with negative stool examinations.

Association between hemoglobin A1c variability and subclinical coronary atherosclerosis in subjects with type 2 diabetes

AIMS We examined the association between hemoglobin A1c (HbA1c) variability and subclinical coronary atherosclerosis in subjects with type 2 diabetes. METHODS We used the multidetector coronary computed tomography data collected from subjects with type 2 diabetes who did not have a history of cardiovascular disease or angina symptoms. HbA1c measurements preceding the date of cardiac imaging were retrospectively collected, and intraindividual SD (HbA1c-SD), CV and adjusted SD of HbA1c measurements were calculated. Subclinical coronary atherosclerosis was defined as calcium score >400 without any cardiac symptoms. RESULTS A total of 595 subjects were categorized according to the median value of each HbA1c variability indicators. The prevalence of subclinical coronary atherosclerosis was higher in higher HbA1c variability group compared with lower HbA1c variability group. Multivariable logistic regression analysis showed that higher HbA1c-SD and -CV were associated with the presence of subclinical coronary atherosclerosis, independent of mean HbA1c level in subjects with diabetes duration ≤10 years (OR [95% CI]; HbA1c-SD, 2.894 [1.105-7.584]; HbA1c-CV, 2.540 [1.022-6.316]). CONCLUSIONS Long-term stabilization of blood glucose level might be important in preventing subclinical coronary atherosclerosis in subjects with earlier period of type 2 diabetes.

Impact of Percutaneous Coronary Intervention for Chronic Total Occlusion in Non–Infarct-Related Arteries in Patients With Acute Myocardial Infarction (from the COREA-AMI Registry)

Chronic total occlusion (CTO) in a non-infarct-related artery (IRA) is an independent predictor of clinical outcomes in patients with acute myocardial infarction (AMI). This study evaluated the impact of successful percutaneous coronary intervention (PCI) for CTO of a non-IRA on the long-term clinical outcomes in patients with AMI. A total of 4,748 patients with AMI were consecutively enrolled in the Convergent Registry of Catholic and Chonnam University for AMI registry from January 2004 to December 2009. We enrolled 324 patients with CTO in a non-IRA. To adjust for baseline differences, propensity matching (96 matched pairs) was used to compare successful PCI and occluded CTO for the treatment of CTO in non-IRA. The primary clinical end points were all-cause mortality and a composite of the major adverse cardiac events, including cardiac death, MI, stroke, and any revascularization during the 5-year follow-up. Patients who received successful PCI for CTO of non-IRA had lower rates of all-cause mortality (16.7% vs 32.3%, hazard ratio 0.459, 95% CI 0.251 to 0.841, p = 0.012) and major adverse cardiac events (21.9% vs 55.2%, hazard ratio 0.311, 95% CI 0.187 to 0.516, p <0.001) compared with occluded CTO group. Subgroup analyses revealed that successful PCI resulted in a better mortality rate in patients with normal renal function compared to patients with chronic kidney disease (p = 0.010). In conclusion, successful PCI for CTO of non-IRA is associated with improved long-term clinical outcomes in patients with AMI.

Status of hypertension and coronary stenosis in asymptomatic type 2 diabetic patients: Analysis from Coronary Computed Tomographic Angiography Registry

BACKGROUND Limited data exist regarding the prevalence of coronary artery disease (CAD) as well as clinical outcomes in asymptomatic diabetic patients with normotension, controlled hypertension, and uncontrolled hypertension. METHODS We enrolled 935 consecutive asymptomatic type 2 diabetic patients without known CAD. Coronary computed tomography angiography was used to evaluate the prevalence and severity of CAD. Blood pressure was measured at baseline. Patients were assigned to one of the three groups: normotension (n=314), controlled hypertension (systolic blood pressure (SBP)< 140 mm Hg with treatment, n=458), or uncontrolled hypertension (SBP ≥ 140 mm Hg with or without treatment, n=163). RESULTS Obstructive CAD (≥ 50% stenosis) increased from the prevalence in normotensive patients (33%) to that in patients with controlled (40%) or uncontrolled hypertension (52%) (p=0.003). The incidence of obstructive CAD in multivessel or left main CAD also increased across the three groups (13%, 21%, 32%, respectively, p<0.001). A multivariate logistic regression analysis showed that uncontrolled hypertension was an independent predictor of obstructive CAD (adjusted odds ratio, 2.13; 95% confidence interval (CI), 1.42 to 3.21, p<0.001). During a median follow-up of 3.1 years, uncontrolled hypertension was associated with increased risk of cardiac death or myocardial infarction compared to the risk in normotensive patients (hazard ratio, 6.11; 95% CI, 1.65 to 22.6, p=0.007). CONCLUSION In asymptomatic type 2 diabetic patients, uncontrolled hypertension was associated with increased risk of CAD and poor clinical outcomes.

Contrast Volume/Raw eGFR Ratio for Predicting Contrast-Induced Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention for Myocardial Infarction

Background: Considering that contrast medium is excreted through the whole kidney in a similar manner to drug excretion, the use of raw estimated glomerular filtration rate (eGFR) rather than body surface area (BSA)-normalized eGFR is thought to be more appropriate for evaluating the risk of contrast-induced acute kidney injury (CI-AKI). Methods: This study included 2,189 myocardial infarction patients treated with percutaneous coronary intervention. Logistic regression analysis was performed to identify the independent risk factors. We used receiver-operating characteristic (ROC) curves to compare the ratios of contrast volume (CV) to eGFR with and without BSA normalization in predicting CI-AKI. Results: The area under the curve (AUC) of the ROC curve for the model including all the significant variables such as diabetes mellitus, left ventricular ejection fraction, preprocedural glucose, and the CV/raw modification of diet in renal disease (MDRD) eGFR ratio was 0.768 [95% confidence interval (CI), 0.720-0.816; p < 0.001]. When the CV/raw MDRD eGFR ratio was used as a single risk value, the AUC of the ROC curve was 0.650 (95% CI, 0.590-0.711; p < 0.001). When the CV/MDRD eGFR ratio with BSA normalization ratio was used, the AUC of the ROC curve further decreased to 0.635 (95% CI, 0.574-0.696; p < 0.001). The difference between the two AUCs was significant (p = 0.002). Conclusions: Raw eGFR is a better predictor for CI-AKI than BSA-normalized eGFR.

Computed Tomography Angiography Images of Coronary Artery Stenosis Provide a Better Prediction of Risk Than Traditional Risk Factors in Asymptomatic Individuals With Type 2 Diabetes: A Long-term Study of Clinical Outcomes

OBJECTIVE We investigated the efficacy of coronary computed tomography angiography (CCTA) in predicting the long-term risks in asymptomatic patients with type 2 diabetes and compared it with traditional risk factors. RESEARCH DESIGN AND METHODS We analyzed 933 patients with asymptomatic type 2 diabetes who underwent CCTA. Stenosis was considered obstructive (≥50%) in each coronary artery segment using CCTA. The extent and severity scores for coronary artery disease (CAD) were evaluated. The primary end point was major adverse cardiovascular events (MACE), including all-cause mortality, nonfatal myocardial infarction, and late coronary revascularization during a mean follow-up period of 5.5 ± 2.1 years. RESULTS Ninety-four patients with MACE exhibited obstructive CAD with a greater extent and higher severity scores (P < 0.001 for all). After adjusting for confounding risk factors, obstructive CAD remained an independent predictor of MACE (hazard ratio 3.11 [95% CI 2.00–4.86]; P < 0.001]). The performance of a risk prediction model based on C-statistics was significantly improved (C-index 0.788 [95% CI 0.747–0.829]; P = 0.0349) upon the addition of a finding of obstructive CAD using CCTA to traditional risk factors, including age, male, hypertension, hyperlipidemia, smoking, estimated glomerular filtration rate, and HbA1c. Both integrated discrimination improvement (IDI) and net reclassification improvement (NRI) analyses further supported this finding (IDI 0.046 [95% CI 0.020–0.072], P < 0.001, and NRI 0.55 [95% CI 0.343–0.757], P < 0.001). In contrast, the risk prediction power of the coronary artery calcium score remained unimproved (C-index 0.740, P = 0.547). CONCLUSIONS Based on our data, the addition of CCTA-detected obstructive CAD to models that include traditional risk factors improves the predictions of MACE in asymptomatic patients with type 2 diabetes.

HDL Cholesterol Level Is Associated with Contrast Induced Acute Kidney Injury in Chronic Kidney Disease Patients Undergoing PCI

Chronic kidney disease (CKD) is a significant risk factor for contrast induced acute kidney injury (CI-AKI) after percutaneous coronary intervention (PCI). This study included 1592 CKD patients extracted from a prospective multicenter, all comer-based registry of patients undergoing PCI. In multivariate logistic analysis for CI-AKI development, a significant linear trend was observed between the quartiles of HDL-C (quartile 1 vs. 2: odds ratio [OR], 0.716; 95% confidence interval [CI], 0.421–1.219; quartile 1 vs. 3: OR, 0.534; 95% CI, 0.301–0.947; quartile 1 vs. 4: OR, 0.173; 95% CI, 0.079–0.377; P for trend < 0.001). HDL-C quartiles were also negatively correlated with the incidence of CI-AKI; 19.0%, 12.1%, 8.7%, and 3.7% for quartile 1(Q1) (<34 mg/dL), Q2 (34–40 mg/dL), Q3 (40–48 mg/dL), and Q4 (>48 mg/dL) respectively (P < 0.001 overall and for the trend). Multivariate Cox regression analysis for the long term mortality, the highest HDL-C quartile was associated with decreased mortality compared with the lowest HDL-C quartile (hazard ratio [HR] 0.516, 95% CI, 0.320–0.832, P = 0.007). Our study suggests more intensive strategies should be considered for preventing CI-AKI in CKD patients with low serum HDL-C level who is planned for PCI.