Difference in basic concept of coronary bifurcation intervention between Korea and Japan. Insight from questionnaire in experts of Korean and Japanese bifurcation clubs

Impact of stent strut link location in proximal balloon edge dilation technique for bifurcation percutaneous coronary intervention

The single-stent strategy has generally been accepted as the default approach to bifurcation percutaneous coronary intervention. We have proposed the proximal balloon edge dilation (PBED) technique to prevent stent deformation during side branch (SB) dilation. This bench study aimed to evaluate the impact of stent link location and stent design on stent deformation, obstruction by stent struts at a jailed SB ostium, and incomplete stent apposition in the proximal optimization technique (POT)-PBED procedure. A coronary bifurcation model was used. We intentionally set the absence or presence of stent link on the carina (link-free or link-connect) under videoscope observation and compared stent parameters between 3- and 2-link stents (n = 5 each, n = 20 total). In the link-free group, the SB jailing rate of 3-link stents was significantly higher than that of 2-link stents (15.5 ± 5.1% vs. 6.6 ± 1.2%, p = 0.009). In the link-connect group, the SB jailing rate of 3-link stents was significantly lower than that of 2-link stents (30.0 ± 4.5% vs. 39.0 ± 2.6%, p = 0.009). In the bifurcation segment, the rate of incomplete stent apposition was significantly lower for 3-link stents of the link-connect group than for 2-link stents of the link-connect group (3.3 ± 4.2% vs. 19.0 ± 7.8%, p = 0.009). For both stent designs, ellipticity ratio was higher for link-connect group than link-free group. Link location as well as stent cell design greatly impacted stent deformation during the POT-PBED procedure.

Impact of preceding acetylcholine provocation testing on following coronary physiological assessment during an interventional diagnostic procedure

BACKGROUND

Intracoronary acetylcholine (ACh) provocation test and coronary physiological assessment are useful interventional diagnostic procedures for evaluating ischemia with no obstructive coronary arteries (INOCA). However, the appropriate sequential order of the diagnostic procedures has been a matter of debate. We investigated the impact of preceding ACh provocation on following coronary physiological assessment.

METHODS

Patients suspected of INOCA underwent invasive coronary physiological assessment using thermodilution method and were divided into two groups according to the implementation of ACh provocation test. The ACh group was further divided into the positive and negative ACh groups. In the ACh group, intracoronary ACh provocation was performed before the invasive coronary physiological assessment. The main interest of this study was to compare coronary physiological indices among the no ACh, negative ACh, and positive ACh groups.

RESULTS

Of 120 patients, the no ACh, and negative and positive ACh groups included 46 (38.3 %), 36 (30.0 %), and 38 (31.7 %), respectively. Fractional flow reserve was lower in the no ACh group than in the ACh group. Resting mean transit time was significantly longer in the positive ACh group, followed by the no ACh and negative ACh groups (1.22 ± 0.55 vs. 1.00 ± 0.46 vs. 0.74 ± 0.36 s, p < 0.001). Index of microcirculatory resistance and coronary flow reserve did not differ significantly among the three groups.

CONCLUSIONS

Preceding ACh provocation influenced following physiological assessment, particularly when ACh test was positive. Further studies are warranted to determine which interventional diagnostic procedure, ACh provocation or physiological assessment, should be preceded in the invasive evaluation of INOCA.

Factors Associated with Impaired Resistive Reserve Ratio and Microvascular Resistance Reserve

Coronary microvascular dysfunction (CMD) is described as an important subset of ischemia with no obstructive coronary artery disease. Resistive reserve ratio (RRR) and microvascular resistance reserve (MRR) have been proposed as novel physiological indices evaluating coronary microvascular dilation function. The aim of this study was to explore factors associated with impaired RRR and MRR. Coronary physiological indices were invasively evaluated in the left anterior descending coronary artery using the thermodilution method in patients suspected of CMD. CMD was defined as a coronary flow reserve <2.0 and/or index of microcirculatory resistance ≥25. Of 117 patients, 26 (24.1%) had CMD. RRR (3.1 ± 1.9 vs. 6.2 ± 3.2, p < 0.001) and MRR (3.4 ± 1.9 vs. 6.9 ± 3.5, p < 0.001) were lower in the CMD group. In the receiver operating characteristic curve analysis, RRR (area under the curve 0.84, p < 0.001) and MRR (area under the curve 0.85, p < 0.001) were both predictive of the presence of CMD. In the multivariable analysis, previous myocardial infarction, lower hemoglobin, higher brain natriuretic peptide levels, and intracoronary nicorandil were identified as factors associated with lower RRR and MRR. In conclusion, the presence of previous myocardial infarction, anemia, and heart failure was associated with impaired coronary microvascular dilation function. RRR and MRR may be useful to identify patients with CMD.

Ten-Year Trends in Coronary Bifurcation Percutaneous Coronary Intervention: Prognostic Effects of Patient and Lesion Characteristics, Devices, and Techniques

Background

Despite advances in devices and techniques, coronary bifurcation lesion remains a challenging lesion subset in the field of percutaneous coronary intervention (PCI). We evaluate 10‐year trends in bifurcation PCI and their effects on patient outcomes.

Methods and Results

We analyzed 10‐year trends in patient/lesion characteristics, devices, PCI strategy, stent optimization techniques, and clinical outcomes using data from 5498 patients who underwent bifurcation PCI from 2004 to 2015. Clinical outcomes 2 years after the index procedure were evaluated in terms of target vessel failure (a composite of cardiac death, myocardial infarction, and target vessel revascularization) and a patient‐oriented composite outcome (a composite of all‐cause death, myocardial infarction, and any revascularization). During the 10‐year study period, patient and lesion complexity, such as multivessel disease, diabetes mellitus, chronic kidney disease, and left main bifurcation, increased continuously (all P<0.001). The risk of target vessel failure or patient‐oriented composite outcome decreased continuously from 2004 to 2015 (target vessel failure: from 12.3% to 6.9%, log‐rank P<0.001; patient‐oriented composite outcome: from 13.6% to 9.3%, log‐rank P<0.001). The use of a second‐generation drug‐eluting stent and decreased target vessel failure risk in true bifurcation lesions were the major contributors to improved patient prognosis (interaction P values were <0.001 and 0.013, respectively).

Conclusions

During the past decade of bifurcation PCI, patient and lesion characteristics, devices, PCI techniques, and patient prognosis have all significantly changed. Despite increased patient and lesion complexity, clinical outcomes after bifurcation PCI have improved, mainly because of better devices and more widespread adoption of procedural optimization techniques and appropriate treatment strategies.

Registration

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01642992 and NCT03068494.