Jae-Hyung Roh

Stress Myocardial Perfusion CT in Patients Suspected of Having Coronary Artery Disease: Visual and Quantitative Analysis—Validation by Using Fractional Flow Reserve

PURPOSEnTo assess the diagnostic accuracy of stress myocardial perfusion computed tomography (CT) by using visual and quantitative analytic methods in patients with coronary artery disease, with fractional flow reserve (FFR) as a reference standard.nnnMATERIALS AND METHODSnThe institutional review board approved the study, and written informed consent was obtained from all patients. The diagnostic accuracy of myocardial perfusion CT was assessed for 75 patients who underwent myocardial perfusion CT and conventional coronary angiography with reference to hemodynamically significant stenosis, defined as the presence of an FFR of 0.8 or less or an angiographically severe (≥90%) stenosis. Results of quantitative analysis of myocardial perfusion CT data were compared with those of visual analysis by using areas under the receiver operating characteristic curve (AUCs).nnnRESULTSnAmong the 75 patients and 210 epicardial arteries, 61 patients (81%) with 86 arteries (41%) had hemodynamically significant stenosis. The per-patient sensitivity and specificity of the visual assessment of myocardial perfusion CT data for all patients were 89% and 86%, respectively. At per-vessel analysis, the sensitivities and specificities, respectively, of myocardial perfusion CT were 80% and 95% for all vessels, 85% and 100% for 63 vessels with severe coronary calcification (defined as an Agatston score > 400), and 76% and 91% for 56 vessels in patients with multivessel disease. In severely calcified vessels, visual assessment of myocardial perfusion CT data in combination with CT angiography provided incremental value over CT angiography alone for the detection of myocardial ischemia (integrated discrimination improvement index, 0.38; P < .001). Quantitative assessment of transmural perfusion ratio had a lower AUC than visual analysis of myocardial perfusion CT (0.759 vs 0.877, P = .002).nnnCONCLUSIONnStress myocardial perfusion CT provides incremental value over CT angiography in patients with a high calcium score for the detection of myocardial ischemia as defined by FFR.

Randomized Comparisons Between Different Stenting Approaches for Bifurcation Coronary Lesions With or Without Side Branch Stenosis

OBJECTIVESnThis study sought to evaluate the optimal percutaneous coronary intervention techniques using drug-eluting stents for bifurcation coronary lesions.nnnBACKGROUNDnThe optimal bifurcation stenting technique needs to be evaluated.nnnMETHODSnThe trial included 2 randomization studies separated by the presence of side branch (SB) stenosis for patients having non-left main bifurcation lesions. For 306 patients without SB stenosis, the routine final kissing balloon or leave-alone approaches were compared. Another randomization study compared the crush or single-stent approaches for 419 patients with SB stenosis.nnnRESULTSnBetween the routine final kissing balloon and leave-alone groups for nondiseased SB lesions, angiographic restenosis occurred in 17.9% versus 9.3% (p=0.064), comprising 15.1% versus 3.7% for the main branch (p=0.004) and 2.8% versus 5.6% for the SB (p=0.50) from 214 patients (69.9%) receiving 8-month angiographic follow-up. Incidence of major adverse cardiac events including death, myocardial infarction, or target vessel revascularization over 1 year was 14.0% versus 11.6% between the routine final kissing balloon and leave-alone groups (p=0.57). In another randomization study for diseased SB lesions, 28.2% in the single-stent group received SB stents. From 300 patients (71.6%) receiving angiographic follow-up, between the crush and single-stent groups, angiographic restenosis rate was 8.4% versus 11.0% (p=0.44), comprising 5.2% versus 4.8% for the main branch (p=0.90) and 3.9% versus 8.3% for the SB (p=0.12). One-year major adverse cardiac events rate between the crush and single-stent groups was 17.9% versus 18.5% (p=0.84).nnnCONCLUSIONSnAngiographic and clinical outcomes were excellent after percutaneous coronary intervention using drug-eluting stents with any stent technique for non-left main bifurcation lesions once the procedure was performed successfully.

Determinants and Prognostic Significance of Periprocedural Myocardial Injury in Patients With Successful Percutaneous Chronic Total Occlusion Interventions

OBJECTIVESnThis study sought to evaluate the determinants and prognostic implications of periprocedural myocardial injury (PMI) in successful percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs).nnnBACKGROUNDnThere are limited studies addressing the risk factors and clinical implication of PMI in patients undergoing CTO-PCI.nnnMETHODSnWe examined 1,058 consecutive CTO patients who underwent successful drug-eluting stent implantation and serial measurements of creatine kinase-myocardial band (CK-MB) values between March 2003 and August 2014. PMI was defined as elevations of CK-MB >3 times the upper reference limit (URL).nnnRESULTSnPMI occurred in 121 patients (11.4%). Multivariable analysis revealed that the presence of renal failure (odds ratio [OR]: 4.25; 95% confidence interval [CI]: 1.59 to 11.35; pxa0= 0.004), attempted retrograde approach (OR: 2.27; 95% CI: 1.34 to 3.84; pxa0= 0.002), concomitant non-target lesion intervention (OR: 1.74; 95% CI: 1.17 to 2.59; pxa0= 0.006), and stent number (OR: 1.38; 95% CI: 1.08 to 1.77; pxa0= 0.011) were predictors associated with PMI. During a median follow-up of 4.4 years, PMI was associated with an increased risk of mortality (adjusted hazard ratio: 1.86; 95% CI: 1.09 to 3.17; pxa0=xa00.02). These findings were also consistent when higher CK-MB cutoff was used to define PMI. Although there was axa0trend toward higher all-cause mortality with increasing peak CK-MB levels, in multivariable analyses, this association was statistically significant only for peak CK-MB levels of >10 times the URL.nnnCONCLUSIONSnPMI was associated with an increased risk of long-term mortality after successful CTO-PCI. Patients with renal insufficiency, those who require more stents, multiple lesion treatment, and retrograde approach have a higher likelihood of having PMI.

Which technique for double stenting in unprotected left main bifurcation coronary lesions

Unprotected left main (LM) bifurcation coronary lesions are challenging for interventionists because these lesions are associated with relatively poor outcomes after percutaneous coronary intervention (PCI). Although the single-stent technique is a default treatment strategy for LM bifurcation lesions, elective double stenting is still used in patients with severely diseased side branches. The crush technique and its variants, the culotte technique and the simultaneous kissing stent technique, are applicable for distal LM disease, but none of these has proven to be superior to the others. Good long-term clinical outcomes are closely related to procedural success and optimisation of the stenting technique. The use of kissing balloon inflation during any double-stent technique is known to be an independent predictor of good angiographic and clinical outcomes by avoiding incomplete apposition or expansion. Moreover, procedural guidance using intravascular ultrasound may improve outcomes by helping to determine the appropriate stenting technique and optimise the stent procedure. Therefore, more attention should be paid to optimising the chosen technique than to choosing among techniques.

Anatomical or Functional Evaluation as an Initial Test for Stable Coronary Artery Disease: A Propensity Score Analysis

Little data are available to compare the clinical implications of coronary angiography (CAG) or myocardial perfusion imaging (MPI) as an initial evaluation for stable coronary artery disease (CAD). Methods: From national health insurance claims data in South Korea, patients aged 18 y or older without a known history of CAD, who underwent CAG or MPI for the diagnosis of stable CAD between 2009 and 2013, were enrolled. Patients were divided into CAG (n = 117,134) and MPI (n = 19,932) groups. The primary endpoint, defined as a composite of all-cause death and myocardial infarction, was compared by a propensity score analysis between the 2 groups. Results: There was a significant increase (39%) in the annual rate of CAG from 23,985 in 2009–2010 to 33,373 in 2012–2013. However, a substantial reduction (41%) in the annual MPI rate was also noted from 6,389 in 2009–2010 to 3,790 in 2012–2013. During the follow-up period (median, 2.4 y; interquartile range, 1.5–3.5), coronary revascularization was more frequently performed in the CAG group (adjusted hazard ratio [aHR] of CAG, 24.15; 95% confidence interval [CI], 19.66–29.68; P < 0.001). However, the incidence of the primary endpoint was significantly higher in the CAG group (aHR, 1.26; 95% CI, 1.17–1.36; P < 0.001). The individual endpoints of death (aHR, 1.16; 95% CI, 1.06–1.25; P = 0.001) and myocardial infarction (aHR, 1.95; 95% CI, 1.60–2.36; P < 0.001) were also higher in the CAG group. Conclusion: As an initial diagnostic test in patients with stable CAD, MPI is associated with a better clinical outcomes than CAG.

Effect of Beta Blockers and Renin-Angiotensin System Inhibitors on Survival in Patients With Acute Myocardial Infarction Undergoing Percutaneous Coronary Intervention.

AbstractBecause it remains uncertain whether &bgr;-blockers (BBs) and/or renin–angiotensin system inhibitors benefit a broad population of acute myocardial infarction (AMI) patients, we sought to evaluate the effectiveness of these drugs in improving survival for post-AMI patients who underwent a percutaneous coronary intervention (PCI).From the nationwide data of the South Korea National Health Insurance, 33,390 patients with a diagnosis of AMI who underwent a PCI between 2009 and 2013 and survived at least 30 days were included in this study. We evaluated the risk of all-cause death for patients treated with both BB and angiotensin-converting enzyme inhibitor (ACEI)/angiotensin II receptor antagonist (ARB) (nu200a=u200a16,280), only BB (nu200a=u200a3683), and only ACEI/ARB (nu200a=u200a9849), with the drug-untreated patients (nu200a=u200a3578) as the reference.Over a median follow-up of 2.4 years, although treated patients displayed a trend toward improved survival, there were no significant differences in the adjusted risk of all-cause death when patients were treated with both drugs (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.70–1.06, Pu200a=u200a0.154), BB (HR 0.88, 95% CI 0.68–1.14, Pu200a=u200a0.325), or ACEI/ARB (HR 0.84, 95% CI 0.68–1.04, Pu200a=u200a0.111). No additional benefit was found for the combination therapy compared with either isolated BB (HR 0.98, 95% CI 0.80–1.21, Pu200a=u200a0.856) or ACEI/ARB (HR 1.03, 95% CI 0.89–1.19, Pu200a=u200a0.727) therapy.Treatment with BB and/or ACEI/ARB has limited effect on survival in unselected nonfatal AMI patients who undergo PCI.

In vivo validation of mathematically derived fractional flow reserve for assessing haemodynamics of coronary tandem lesions

AIMSnOur aim was to propose a prediction model for the post-stenting fractional flow reserve (FFRd,pred) at a position distal to the tandem lesion.nnnMETHODS AND RESULTSnUsing the FFR at a position proximal to the tandem lesion (FFRp), and the FFR gradients across proximal (ΔFFRp) and distal (ΔFFRd) stenoses, FFRd,pred after treating either the distal or proximal lesion was predicted as FFRp-ΔFFRp/(1-1.33kΔFFRd) or FFRp-ΔFFRd/(1-1.33ΔFFRp), respectively. The flow fraction of the distal main branch (k) was estimated using the diameter ratio of side to distal main branches. For in vivo validation, 50 patients with a tandem lesion (diameter stenosis >50%) were evaluated. Compared to the conventional model that did not consider side branch flow, our predicted FFR showed closer correlation with the measured FFR (R2=0.83 vs. 0.57) and significant reduction in mean absolute errors (0.034±0.028 vs. 0.053±0.049, p<0.001). In particular, with a large side branch and low baseline FFR, decision making using the current model had greater predictive ability than with the conventional model.nnnCONCLUSIONSnBy predicting which stenosis is more severe and/or whether the remaining lesion after the first treatment is functionally significant, a tandem prediction model can help to plan optimised stent implantation.

Time-dependent reversal of significant intrapulmonary shunt after liver transplantation

Background/Aims Although the association between intrapulmonary shunt (IPS) and liver cirrhosis is clear, data of repeated contrast echocardiography (CE) before and after liver transplantation (LT) to evaluate factors associated with IPS are limited. Methods Hand-agitated saline was used for CE and, by assessing left-chamber opacification, IPS was classified as grade 0 to 4. Grade 3/4 constituted significant IPS and hepatopulmonary syndrome (HPS) was defined as significant IPS with the arterial partial pressure of oxygen < 70 mmHg. Results Before LT, 253 patients underwent CE and the frequency of significant IPS and HPS were 44% (n = 112) and 7% (n = 17), respectively. Child-Pugh score (odds ratio [OR], 1.345; 95% confidence interval [CI], 1.090 to 1.660; p = 0.006) and arterial oxygen content (OR, 0.838; 95% CI, 0.708 to 0.991; p = 0.039) were independent determinants of significant IPS, whereas direct bilirubin (OR, 1.076; 95% CI, 1.012 to 1.144; p = 0.019) was the only variable associated with HPS. Among 153 patients who underwent successful LT, repeated CE was performed in 97 (63%), which showed significant reductions in IPS grade (from 2.6 ± 1.0 to 1.2 ± 1.3, p < 0.001) and the prevalence of significant IPS (from 56% to 20%, p = 0.038). After adjustment for pre-LT IPS grade, time from LT to repeated CE presented negative linear relationship with post-LT IPS grade (r2 = 0.366, p < 0.001) and was the only determinant of post-LT IPS grade (OR, 1.009; 95% CI, 1.003 to 1.014; p = 0.004). Conclusions Repeated CE is useful to evaluate intrapulmonary vascular change before and after LT. Reversal of IPS after successful LT is time-dependent and follow-up duration should be considered for accurate assessment of IPS after LT.