Chee Hae Kim

Exploring Coronary Circulatory Response to Stenosis and Its Association With Invasive Physiologic Indexes Using Absolute Myocardial Blood Flow and Coronary Pressure

Background: Although invasive physiological assessment for coronary stenosis has become a standard practice to guide treatment strategy, coronary circulatory response and changes in invasive physiological indexes, according to different anatomic and hemodynamic lesion severity, have not been fully demonstrated in patients with coronary artery disease. Methods: One hundred fifteen patients with left anterior descending artery stenosis who underwent both 13N-ammonia positron emission tomography and invasive physiological measurement were analyzed. Myocardial blood flow (MBF) measured with positron emission tomography and invasively measured coronary pressures were used to calculate microvascular resistance and stenosis resistance. Results: With progressive worsening of angiographic stenosis severity, both resting and hyperemic transstenotic pressure gradient and stenosis resistance increased (P<0.001 for all) and hyperemic MBF (P<0.001) and resting microvascular resistance (P=0.012) decreased. Resting MBF (P=0.383) and hyperemic microvascular resistance (P=0.431) were not changed and maintained stable. Both fractional flow reserve and instantaneous wave-free ratio decreased as angiographic stenosis severity, stenosis resistance, and transstenotic pressure gradient increased and hyperemic MBF decreased (all P<0.001). When the presence of myocardial ischemia was defined by both low hyperemic MBF and low coronary flow reserve, the diagnostic accuracy of fractional flow reserve and instantaneous wave-free ratio did not differ, regardless of cutoff values of hyperemic MBF and coronary flow reserve. Conclusions: This study demonstrated how the coronary circulation changes in response to increasing coronary stenosis severity using 13N-ammonium positron emission tomography–derived MBF and invasively measured pressure data. Currently used resting and hyperemic pressure–derived invasive physiological indexes have similar patterns of relationships to the different anatomic and hemodynamic lesion severities. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01366404.

Efficacy and Safety of Adding Omega-3 Fatty Acids in Statin-treated Patients with Residual Hypertriglyceridemia: ROMANTIC (Rosuvastatin-OMAcor iN residual hyperTrIglyCeridemia), a Randomized, Double-blind, and Placebo-controlled Trial

PURPOSE The purpose of this study was to examine the efficacy and safety of adding ω-3 fatty acids to rosuvastatin in patients with residual hypertriglyceridemia despite statin treatment. METHODS This study was a multicenter, randomized, double-blind, placebo-controlled study. After a 4-week run-in period of rosuvastatin treatment, the patients who had residual hypertriglyceridemia were randomized to receive rosuvastatin 20 mg/d plus ω-3 fatty acids 4 g/d (ROSUMEGA group) or rosuvastatin 20 mg/d (rosuvastatin group) with a 1:1 ratio and were prescribed each medication for 8 weeks. FINDINGS A total of 201 patients were analyzed (mean [SD] age, 58.1 [10.7] years; 62.7% male). After 8 weeks of treatment, the percentage change from baseline in triglycerides (TGs) and non-HDL-C was significantly greater in the ROSUMEGA group than in the rosuvastatin group (TGs: -26.3% vs -11.4%, P < 0.001; non-HDL-C: -10.7% vs -2.2%, P = 0.001). In the linear regression analysis, the lipid-lowering effect of ω-3 fatty acids was greater when baseline TG or non-HDL-C levels were high and body mass index was low. The incidence of adverse events was not significantly different between the 2 groups. IMPLICATIONS In patients with residual hypertriglyceridemia despite statin treatment, a combination of ω-3 fatty acids and rosuvastatin produced a greater reduction of TGs and non-HDL-C than rosuvastatin alone. Further study is needed to determine whether the advantages of this lipid profile of ω-3 fatty acids actually leads to the prevention of cardiovascular event. ClinicalTrials.gov identifier: NCT03026933.

Prognostic implication of thermodilution coronary flow reserve in patients with indeterminate pressure-bounded coronary flow reserve

BACKGROUND Recently, the concept of pressure-bounded coronary flow reserve (PB-CFR) has been introduced. However, using pressure-only data, a substantial proportion of patients could not be classified into high or low PB-CFR and remained as indeterminate PB-CFR. The current study evaluated the prognostic implication of thermodilution-based CFR (thermo-CFR) in patients with indeterminate PB-CFR. METHODS Among 199 patients (211 lesions) with indeterminate PB-CFR, 170 patients (179 lesions) with deferral of revascularization were analyzed for the current study. The rates of patient-oriented composite outcomes (POCO, a composite of all-cause mortality, any myocardial infarction, and any ischemia-driven revascularization) were compared according to thermo-CFR. All patients underwent fractional flow reserve (FFR) and thermo-CFR measurements. Thermo-CFR ≤ 2.0 was classified as low thermo-CFR. The median follow-up duration was 1350.0 (Q1-Q3 1252.0-1468.0) days. RESULTS Mean angiographic percent diameter stenosis, FFR, and thermo-CFR were 42.3 ± 13.9, 0.84 ± 0.06, and 3.10 ± 1.15, respectively. Among 170 patients, 36 patients (21.2%) showed low thermo-CFR. Patients with low thermo-CFR showed significantly higher rate of POCO compared to those with high thermo-CFR (30.6% vs. 3.0%, HR 12.117, 95% CI 3.854-38.091, p < 0.001). Adding thermo-CFR to a prediction model with FFR significantly increased discrimination and reclassification index for the risk of POCO (c-index 0.545 vs. 0.766, p = 0.002, category-free net reclassification index 1.169, p < 0.001, relative integrated discrimination index 31.828, p < 0.001). CONCLUSIONS Patients with low thermo-CFR showed a significantly higher risk of POCO compared to those with high thermo-CFR among patients with indeterminate PB-CFR. Thermo-CFR showed additional prognostic implication, in addition to FFR, in patients with indeterminate PB-CFR.

VARIABILITY OF FRACTIONAL FLOW RESERVE ACCORDING TO THE VARIOUS METHODS TO INDUCE HYPEREMIA

Concerns have been raised regarding the variability of FFR (fractional flow reserve) due to the routes of administration and different hyperemic agents targeting different receptors to induce maximal hyperemia. A total of 644 intermediate coronary lesions from 622 patients with coronary artery

Infective Endocarditis Associated with Transcatheter Aortic Valve Replacement: Potential Importance of Local Trauma for a Deadly Nidus

Recently, transcatheter aortic valve replacement (TAVR) has emerged as an alternative for the treatment of severe symptomatic aortic stenosis patients. Although experience with TAVR is increasing exponentially, few cases of post-TAVR endocarditis are reported. We present a case of 76-year-old man with infective endocarditis after TAVR who was definitely diagnosed by echocardiography.