Prognostic Value of Microvascular Resistance Reserve Measured Immediately After PCI in Stable Coronary Artery Disease.

BACKGROUND: Microvascular resistance reserve (MRR) has been proposed as a specific metric to quantify coronary microvascular function. The long-term prognostic value of MRR measured in stable patients immediately after percutaneous coronary intervention (PCI) is unknown. This study sought to determine the prognostic value of MRR measured immediately after PCI in patients with stable coronary artery disease. METHODS: This study included 502 patients with stable coronary artery disease who underwent elective PCI and coronary physiological measurements, including pressure and flow estimation using a bolus thermodilution method after PCI. MRR was calculated as coronary flow reserve divided by fractional flow reserve times the ratio of mean aortic pressure at rest to that at maximal hyperemia induced by hyperemic agents. An abnormal MRR was defined as ≤2.5. Major adverse cardiac events (MACEs) were defined as a composite of all-cause mortality, any myocardial infarction, and target-vessel revascularization. RESULTS: During a median follow-up of 3.4 years, the cumulative MACE rate was significantly higher in the abnormal MRR group (12.5 versus 8.3 per 100 patient-years; hazard ratio 1.53 [95% CI, 1.10-2.11]; P<0.001). A higher all-cause mortality rate primarily drove this difference. On multivariable analysis, a higher MRR value was independently associated with lower MACE and lower mortality. When comparing 4 subgroups according to MRR and the index of microcirculatory resistance, patients with both abnormal MRR and index of microcirculatory resistance (≥25) had the highest MACE rate. CONCLUSIONS: An abnormal MRR measured immediately after PCI in patients with stable coronary artery disease is an independent predictor of MACE, particularly all-cause mortality.

Sex-Specific Disparities in Clinical Outcomes After Transcatheter Aortic Valve Replacement Among Different Racial Populations.

Background: Sex-related disparities in clinical outcomes following transcatheter aortic valve replacement (TAVR) and the impact of sex on clinical outcomes after TAVR among different racial groups are undetermined. Objectives: This study assessed whether sex-specific differences in baseline clinical and anatomical characteristics affect clinical outcomes after TAVR and investigated the impact of sex on clinical outcomes among different racial groups. Methods: The TP-TAVR (Trans-Pacific TAVR) registry is a multinational cohort study of patients with severe aortic stenosis who underwent TAVR at 2 major centers in the United States and 1 major center in South Korea. The primary outcome was a composite of death from any cause, stroke, or rehospitalization after 1 year. Results: The incidence of the primary composite outcome was not significantly different between sexes (27.9% in men vs 28% in women; adjusted HR: 0.97; 95% CI: 0.79-1.20). This pattern was consistent in Asian (23.5% vs 23.3%; adjusted HR: 0.99; 95% CI: 0.69-1.41) and non-Asian (30.8% vs 31.6%; adjusted HR: 0.95; 95% CI: 0.72-1.24) cohorts, without a significant interaction between sex and racial group (P for interaction = 0.74). The adjusted risk for all-cause mortality was similar between sexes, regardless of racial group. However, the adjusted risk of stroke was significantly lower in male patients than in female patients, which was more prominent in the non-Asian cohort. Conclusions: Despite significantly different baseline and procedural characteristics, there were no sex-specific differences in the adjusted 1-year rates of primary composite outcomes and all-cause mortality, regardless of different racial groups. (Transpacific TAVR registry [TP-TAVR]; NCT03826264).

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.

Race-Specific Impact of Conventional Surgical Risk Score on 1-Year Mortality After Transcatheter Aortic Valve Replacement.

Background: Interracial differences in the distribution and prognostic value of conventional Society of Thoracic Surgeons (STS) score on long-term mortality after transcatheter aortic valve replacement (TAVR) are uncertain. Objectives: This study aims to compare the impact of STS scores on clinical outcomes at 1-year after TAVR between Asian and non-Asian populations. Methods: We used the Trans-Pacific TAVR (TP-TAVR) registry, a multinational multicenter, observational registry involving patients undergoing TAVR at 2 major centers in the United States and 1 major center in Korea. Patients were classified into 3 groups (low, intermediate, and high-risk) according to the STS score and compared between STS risk groups and race. The primary outcome was all-cause mortality at 1-year. Results: Among 1,412 patients, 581 were Asian and 831 were non-Asian. The distribution of the STS risk score group was different between Asian and non-Asian groups (62.5% low-, 29.8% intermediate-, and 7.7% high-risk in Asian vs 40.6% low-, 39.1% intermediate-, and 20.3% high-risk in non-Asian). In the Asian population, the all-cause mortality at 1-year was substantially higher in the high-risk STS group than in the low- and intermediate-risk groups (3.6% low-risk, 8.7% intermediate-risk, and 24.4% high-risk; log-rank P < 0.001), which was primarily driven by noncardiac mortality. In the non-Asian group, there was a proportional increase in all-cause mortality at 1-year according to the STS risk category (5.3% low-risk, 12.6% intermediate-risk, and 17.8% high-risk; log-rank P < 0.001). Conclusions: In this multiracial registry of patients with severe aortic stenosis who underwent TAVR, we identified a differential proportion and prognostic impact of STS score on 1-year mortality between Asian and non-Asian patients (TP-TAVR [Transpacific TAVR Registry]; NCT03826264).

Efficacy of Optical Coherence Tomography-Guided Primary Percutaneous Coronary Intervention in Patients with Acute Coronary Syndrome.

Background: Optical coherence tomography (OCT) is currently used as a guide for percutaneous coronary intervention (PCI), however its clinical benefit in comparison with intravascular ultrasound (IVUS) remains unclear in patients with acute coronary syndrome (ACS). Objectives: The purpose of this study was to evaluate the clinical efficacy of OCT-guided PCI in comparison with IVUS-guided PCI in patients with ACS. Methods: The study participants comprised 280 consecutive ACS patients who underwent primary PCI for de novo culprit lesions under OCT or IVUS guidance. Results: Compared with the IVUS-guided group, the OCT-guided group had lower Killip classification (p < 0.001) and lower creatinine level at baseline (0.80 ± 0.37 mg/dl vs. 1.13 ± 1.29 mg/dl, p = 0.004). Fluoroscopy time and total procedure time were significantly shorter in the OCT-guided group than in the IVUS-guided group (32 ± 13 min vs. 41 ± 19 min, p < 0.001, and 98 ± 39 min vs. 127 ± 47 min, p = 0.002, respectively). The major adverse cardiovascular event-free survival curves were similar between the OCT- and IVUS-guided groups after adjusting for clinical background using propensity score (log-rank p = 0.328). Conclusions: After adjusting for clinical background, OCT-guided PCI could provide comparable clinical outcomes to IVUS-guided PCI in patients with ACS. Shorter fluoroscopy time and total procedure time with OCT may reduce patient radiation exposure and also improve hospital workflow.

Efficacy of a new generation intracoronary optical coherence tomography imaging system with fast pullback.

OBJECTIVES: We sought to investigate whether a novel, fast-pullback, high-frequency optical coherence tomography (HF-OCT) imaging system enables data acquisition with a reduced amount of contrast agents while retaining the same qualitative and quantitative lesion assessment to conventional OCT. BACKGROUND: The increased amount of administered contrast agents is a major concern when performing intracoronary OCT. METHODS: The present study is a single-center, prospective, observational study including 10 patients with stable coronary artery disease. A total of 28 individual coronary arteries were assessed by both fast-pullback HF-OCT and by conventional OCT. RESULTS: The contrast volume used in each OCT run for the HF-OCT system was significantly lower than for the conventional OCT system (5.0 ± 0.0 mL vs. 7.8 ± 0.7 mL, respectively, with a mean difference of -2.84 [95% confidence interval [CI]: -3.10 to -2.58]). No significant difference was found in the median value of the clear image length between the two OCT systems (74 mm [interquartile range [IQR]; 63, 81], 74 mm [IQR; 71, 75], p = 0.89). Fast-pullback HF-OCT showed comparable measurements to conventional OCT, including minimum lumen area (3.27 ± 1.53 mm2 vs. 3.21 ± 1.53 mm2 , p = 0.27), proximal reference area (7.03 ± 2.28 mm2 vs. 7.03 ± 2.34 mm2 , p = 0.96), and distal reference area (5.93 ± 1.96 mm2 vs. 6.03 ± 2.02 mm2 , p = 0.23). Qualitative OCT findings were comparable between the fast-pullback HF-OCT runs and conventional OCT with respect to identifying lipid-rich plaques, calcifications, layered plaques, macrophages, and cholesterol crystals. CONCLUSION: With the fast pullback function of a novel HF-OCT imaging system, we acquired OCT images using a significantly lower amount of contrast volume while retaining a comparable qualitative and quantitative lesion assessment to conventional OCT.

Clinical Characteristics and Outcomes of Patients Presenting With Acute Myocardial Infarction Without Cardiogenic Shock.

BACKGROUND: Most patients with acute myocardial infarction (AMI) present in the emergency department in a hemodynamically stable condition (i.e., non-cardiogenic shock) (AMI-NCS). However, few studies specifically focused on the clinical characteristics and outcomes of AMI-NCS patients. Temporal trends in clinical characteristics, in-hospital occurrence of in-hospital adverse outcomes, and the effect of primary percutaneous coronary intervention (PPCI) were examined.Methods and Results: Between April 2012 and March 2018, 176,275 AMI-NCS patients (67.7% of the total AMI population; 25.4% female; mean age 68.6±13.1 years) were identified in a nationwide Japanese administrative database. During the 6-year study period, AMI-NCS patients have been getting older and had an increasing burden of comorbidities. The rates of 30-day all-cause mortality and in-hospital complications were 2.6% and 30.5%, respectively. Thirty-day all-cause mortality did not change significantly over time, whereas in-hospital complications, especially major non-cardiac events, increased progressively. On multivariable analyses, higher age, higher Killip class, atrial fibrillation, chronic renal failure, and malignancy were independently associated with both increased 30-day mortality and in-hospital complications. PPCI was independently associated with lower mortality and in-hospital complications. CONCLUSIONS: The clinical background of AMI-NCS patients has been becoming more complex with increasing age and the burden of comorbidities, with increased in-hospital complications. More active and appropriate application of PPCI may further decrease adverse events and improve survival of AMI-NCS patients.

Resources for cardiovascular healthcare associated with 30-day mortality in acute myocardial infarction with cardiogenic shock.

Aims: Although primary percutaneous coronary intervention (PCI) and mechanical circulatory support (MCS), such as extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pumping (IABP), have been widely used for acute myocardial infarction (AMI) patients with cardiogenic shock (AMICS), their in-hospital mortality remains high. This study aimed to investigate the association of cardiovascular healthcare resources with 30-day mortality in AMICS. Methods and results: This was an observational study using a Japanese nationwide administrative data (JROAD-DPC) of 260 543 AMI patients between April 2012 and March 2018. Of these, 45 836 AMICS patients were divided into three categories based on MCS use: with MCS (ECMO with/without IABP), IABP only, or without MCS. Certified hospital density and number of board-certified cardiologists were used as a metric of cardiovascular healthcare resources. We estimated the association of MCS use, cardiovascular healthcare resources, and 30-day mortality. The 30-day mortality was 71.2% for the MCS, 23.9% for IABP only, and 37.8% for the group without MCS. The propensity score-matched and inverse probability-weighted Cox frailty models showed that primary PCI was associated with a low risk for mortality. Higher hospital density and larger number of cardiologists in the responsible hospitals were associated with a lower risk for mortality. Conclusion: Although the 30-day mortality remained extremely high in AMICS, indication of primary PCI and improvement in providing cardiovascular healthcare resources associated with the short-term prognosis of AMICS.

Outcomes of Venoarterial Extracorporeal Membrane Oxygenation Plus Intra-Aortic Balloon Pumping for Treatment of Acute Myocardial Infarction Complicated by Cardiogenic Shock.

Background Clinical outcomes of acute myocardial infarction complicated by cardiogenic shock remain poor with high in-hospital mortality. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been widely used for patients with acute myocardial infarction complicated by cardiogenic shock refractory to conservative therapy, which is likely fatal without mechanical circulatory support. However, whether additional intra-aortic balloon pumping (IABP) use during VA-ECMO support improves clinical outcomes remains controversial. This study sought to investigate prognostic impact of the combined VA-ECMO plus IABP treatment compared with VA-ECMO alone. Methods and Results From the nationwide Japanese administrative case-mix Diagnostic Procedure Combination (DPC), the JROAD (Japanese Registry of All Cardiac and Vascular Diseases)-DPC, we identified 3815 patients with acute myocardial infarction complicated by cardiogenic shock who underwent primary percutaneous coronary intervention and managed with VA-ECMO. Of these, 2964 patients (77.7%) were managed with IABP (VA-ECMO plus IABP), whereas 851 (22.3%) were managed without IABP (VA-ECMO alone). We compared in-hospital, 7-day, and 30-day mortality between the VA-ECMO plus IABP versus the VA-ECMO alone support. Patients managed with VA-ECMO plus IABP demonstrated significantly lower in-hospital, 7-day, and 30-day mortality than those managed with VA-ECMO alone (adjusted odds ratios [95% CI] of 0.47 [95% CI, 0.38-0.59], 0.41 [95% CI, 0.33-0.51], and 0.30 [95% CI, 0.25-0.37], respectively). The findings were consistent in the propensity matching and inverse probability of treatment-weighting models. Conclusions This large-scale, nationwide study demonstrated that the combination of VA-ECMO plus IABP support was associated with significantly lower mortality compared with VA-ECMO support alone in patients presenting with acute myocardial infarction complicated by cardiogenic shock who underwent primary percutaneous coronary intervention.

Discrepancy between plaque vulnerability and functional severity of angiographically intermediate coronary artery lesions.

This study sought to investigate the relationship between physiological severity and plaque vulnerability of intermediate coronary artery stenoses as assessed by fractional flow reserve (FFR) and near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS). We included vessels where both FFR and NIRS-IVUS were performed. A positive FFR was defined as FFR ≤ 0.80. Lipid core burden index of the entire target vessel (TV-LCBI), maximum LCBI in 4 mm (maxLCBI4mm), and maximum plaque burden (PB) were evaluated using NIRS-IVUS. A vulnerable plaque was defined as a lipid-rich plaque (maxLCBI4mm ≥ 400) with large PB (≥ 70%). A total of 59 vessels of 45 patients were included. Median FFR value was 0.75 [interquartile 0.72, 0.82]. An FFR value of ≤ 0.80 was observed in 42 vessels (71%). TV-LCBI (correlation coefficient [CC] = - 0.331, p = 0.011), lesion length (CC = - 0.350, p = 0.007), and PB (CC = - 0.230, p = 0.080) negatively correlated with FFR value, while maxLCBI4mm did not (CC = - 0.156, p = 0.24). The prevalence of vulnerable plaques (26.2% vs. 29.4%, p > 0.99) and mean TV-LCBI, maxLCBI4mm, and PB values were not significantly different between the vessels with FFR ≤ 0.80 and those with FFR > 0.80. In multivariable logistic models, diabetes mellitus (p = 0.003) and hemoglobin A1c (p = 0.012) were associated with the presence of a vulnerable plaque. In conclusion, the results of the present study suggested that FFR may reflect total lipid burden but not necessarily plaque vulnerability. In patients with coronary artery disease and a high likelihood of rapid atherosclerosis progression, such as diabetes mellitus patients, assessing plaque vulnerability in addition to the functional severity of coronary artery lesions may help stratify better the risk of future events.

Layered Plaque in Organic Lesions in Patients With Coronary Artery Spasm.

Background Coronary artery spasm plays a vital role in the pathogenesis of coronary plaques. We sought to investigate the plaque characteristics of co-existing organic lesions in patients with coronary artery spasm in comparison to those without coronary artery spasm by intracoronary optical coherence tomography (OCT). Methods and Results We included 39 patients who presented with a symptom suspected of coronary spastic angina and had an organic lesion, defined as ≥plaque burden of 50% assessed by OCT. Coronary artery spasm was diagnosed by positive acetylcholine provocation test, or by spontaneous spasm detected during coronary angiography. A total of 51 vessels with an organic lesion were identified. Of these, coronary artery spasm was observed in 30 vessels (spasm), while not in 21 vessels (non-spasm). Organic lesions in the spasm vessels, compared with those in the non-spasm vessels, had a higher prevalence of layered plaque (93% versus 38%, P<0.001), macrophages (80% versus 43%, P=0.016), and intraplaque microchannels (73% versus 24%, P<0.001), and lower prevalence of macrocalcification (23% versus 62%, P=0.009) as assessed by OCT. Conclusions Layered plaque, macrophages, and intraplaque microchannels, were frequently observed in organic lesions in patients with coronary artery spasm. These findings suggest that coronary artery spasm induces local thrombus formation as well as active inflammatory response, therefore increasing the risk of rapid plaque progression and ischemic events in patients with coronary artery spasm.