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.

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.

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.

Resistive reserve ratio and microvascular resistance reserve in patients with coronary vasospastic angina.

Patients with epicardial coronary vasospastic angina (VSA) may be likely to have coronary microvascular dysfunction, although mixed results have been reported. The aim of this study was to evaluate coronary microvascular function in detail using novel invasive physiologic indices, such as resistive reserve ratio (RRR) and microvascular resistance reserve (MRR). A total of 45 patients undergoing intracoronary acetylcholine (ACh) provocation test and invasive coronary circulatory evaluation using a thermodilution method were prospectively included. VSA was diagnosed as angiographic vasospasm accompanied by chest pain and/or ischemic electrocardiographic changes by intracoronary injection of ACh. Coronary circulation was assessed with physiologic indices including fractional flow reserve, resting and hyperemic mean transit time (Tmn), coronary flow reserve (CFR), basal resistance index, index of microcirculatory resistance (IMR), RRR, and MRR. Of 45 patients, 23 (51.1%) were diagnosed as having VSA. Patients with positive ACh test had longer resting Tmn (slower coronary flow velocity), higher basal resistance index, and greater RRR and MRR than those without, while fractional flow reserve, CFR, and IMR did not differ significantly between the two groups. In conclusion, although conventional measures such as CFR and IMR failed to show significant differences, RRR and MRR, novel invasive coronary physiologic indices, provided counterintuitive insights that coronary microvascular dilation function was better preserved in patients with VSA than those without.

Hybrid transileocecal portal vein embolization associated with staging laparoscopy for planned major hepatectomy in advanced hepatobiliary cancers.

BACKGROUND: Portal vein embolization (PVE) is widely used to promote the hypertrophy of a future liver remnant (FLR) and reduce posthepatectomy liver failure. The aim of this study was to evaluate the efficacy of transileocecal portal embolization (TIPE) associated with staging laparoscopy (hybrid lap-TIPE) for a planned hepatectomy in advanced hepatobiliary cancers. METHODS: The hybrid lap-TIPE procedure consisted of staging laparoscopy for complete screening of the abdominal cavity with cytoreductive surgery and subsequent TIPE. Data on hybrid lap-TIPE, performed between March 2013 and February 2020, were collected retrospectively. RESULTS: Hybrid lap-TIPE was conducted for 52 patients, and a subsequent TIPE was accomplished in 42 patients (80.8%), since staging laparoscopy detected latent or unresectable factors in 13 patients (25.0%), among which 2 patients with hepatocellular carcinoma and 1 with colorectal liver metastasis received laparoscopic cytoreductive surgery for latent lesions in the FLR. Finally, radical hepatectomy was completed in 36 patients (69.2%), including 3 patients who underwent cytoreductive surgery. The most common operation was an extended right hepatectomy (50.0%), followed by right hepatectomy (30.6%), including 3 hepatopancreatoduodenectomies. The overall morbidity associated with hybrid lap-TIPE and hepatectomy was 7.1% and 41.7%, respectively. The mortality associated with hybrid lap-TIPE and hepatectomy was 0% and 5.6%, respectively. The rates of 2-year survival and 2-year disease-free survival were 64.8% and 61.9%, respectively, after hepatectomy. CONCLUSIONS: Hybrid lap-TIPE is safe and could be a useful treatment option for patients with advanced hepatobiliary cancer because it can help to identify optimal candidates for PVE followed by a planned hepatectomy.

Laparoscopic portal branch ligation of the right caudate lobe concomitant with portal vein embolization for planned right hemihepatectomy in advanced hepatobiliary cancers.

BACKGROUND: The role of ligation of the portal venous branches to the caudate lobe (cPVL) as preparation for planned major hepatectomy is unclear. The aim of this study was to evaluate the efficacy of laparoscopic cPVL (Lap-cPVL) concomitant with transileocolic portal vein embolization of the right portal venous system (rTIPE), namely, Lap-cPVL/rTIPE, for planned right hemihepatectomy (rHx) in advanced hepatobiliary cancer patients. METHODS: Thirty-one patients who underwent rHx after rTIPE with/without Lap-cPVL between March 2013 and March 2020 were enrolled in this study. The Lap-cPVL was performed for the portal branches of the right caudate lobe. RESULTS: Eight of the 31 patients underwent Lap-cPVL/rTIPE. The degree of hypertrophy was significantly increased in Lap-cPVL/rTIPE (19.3%, range 6.5-25.6%) as compared to rTIPE (7.2%, range - 1.1 to 21.2%) (p=0.027). The functional kinetic growth rate was also significantly increased in Lap-cPVL/rTIPE (5.40%, range 2.17-5.97) than that in rTIPE (1.85%, range - 0.22 to 6.45%) (p=0.046). Postoperative liver failure ≧ grade B occurred in 21.7% of patients in rTIPE, while there was no postoperative liver failure ≧ grade B in Lap-cPVL/rTIPE. Mortality rates were zero after rHx in this study. CONCLUSIONS: Lap-cPVL/rTIPE is safe and provides an additional effect on liver hypertrophy in advanced hepatobiliary cancers.

Laparoscopic versus open radical antegrade modular pancreatosplenectomy with artery-first approach in pancreatic cancer.

BACKGROUND: An artery-first approach for pancreatic cancer (PC) is challenging to perform laparoscopically and is mainly performed using an open approach. The aims of this study were to assess the safety and feasibility of laparoscopic radical antegrade modular pancreatosplenectomy (RAMPS) with an artery-first approach (L-aRAMPS) as compared with open aRAMPS (O-aRAMPS) in resectable PC using matched-pair analysis. METHODS: Artery-first approach is an early dissection of the superior mesenteric artery (SMA) from behind the pancreas body as the first surgical step. Data on L-aRAMPS and O-aRAMPS, performed between July 2013 and November 2019, were collected retrospectively. Additionally, the spatial characteristics of the splenic artery were analyzed using computed tomography. RESULTS: Thirty L-aRAMPS and 33 O-aRAMPS for resectable PC were included. After matching, 15 L-aRAMPS were compared with 15 O-aRAMPS. Median intraoperative blood loss and hospital stay were significantly improved in L-aRAMPS compared to O-aRAMPS (30 vs. 220 g, p < 0.001; 12 vs. 16 days, p = 0.049). The overall morbidity was similar in both study groups. The total number of lymph nodes dissected and those harvested from around the SMA and R0 resection was similar in both study groups. We classified the width of the cross section of the pancreas body into three equal parts: the upper, middle, and lower parts of the pancreas; 63% of the splenic artery origin was located in middle and lower parts of the pancreas body. CONCLUSION: L-aRAMPS is technically safe and oncologically feasible to secure favorable surgical outcomes for resectable PC patients.

Fractional Flow Reserve and Quality-of-Life Improvement After Percutaneous Coronary Intervention in Patients With Stable Coronary Artery Disease.

BACKGROUND: Whether the benefit in quality of life (QOL) after percutaneous coronary intervention depends on the severity of the stenosis as determined by fractional flow reserve (FFR) remains unknown. This study sought to investigate the relationship between FFR values and improvement in QOL. METHODS: From the FAME 1 and 2 trials (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation), we identified 706 stable patients with coronary artery disease who had at least 1 lesion with an FFR≤0.80 that was treated with percutaneous coronary intervention and 185 patients with coronary artery disease who had no lesion with an FFR≤0.80 and were treated medically who served as a reference group. QOL was assessed by the European Quality of Life-5 Dimensions index at baseline, 1 month, and 1 year. We assessed the relationship between QOL improvement (defined as the change in European Quality of Life-5 Dimensions index from baseline) and FFR as a continuous value and according to abnormal FFR tertile. RESULTS: QOL improved significantly after percutaneous coronary intervention in each abnormal FFR tertile, whereas it did not change in the reference group. The lowest abnormal FFR subgroup had the greatest improvement in QOL at 1 month ( P<0.001). In mixed-effects models for repeated measures, lower FFR ( P=0.002 for 1 month and 0.049 for 1 year), greater delta FFR ( P=0.021 for 1 month and 0.025 for 1 year), and higher angina class ( P=0.001 for 1 month and <0.001 for 1 year) were associated with the greatest magnitude of QOL improvement at both 1 month and 1 year. CONCLUSIONS: Among patients with stable coronary artery disease, FFR and angina severity predict QOL improvement after percutaneous coronary intervention. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifiers: NCT00267774 and NCT01132495.

Clinical Outcomes and Cost-Effectiveness of Fractional Flow Reserve-Guided Percutaneous Coronary Intervention in Patients With Stable Coronary Artery Disease: Three-Year Follow-Up of the FAME 2 Trial (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation).

BACKGROUND: Previous studies found that percutaneous coronary intervention (PCI) does not improve outcome compared with medical therapy (MT) in patients with stable coronary artery disease, but PCI was guided by angiography alone. FAME 2 trial (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) compared PCI guided by fractional flow reserve with best MT in patients with stable coronary artery disease to assess clinical outcomes and cost-effectiveness. METHODS: A total of 888 patients with stable single-vessel or multivessel coronary artery disease with reduced fractional flow reserve were randomly assigned to PCI plus MT (n=447) or MT alone (n=441). Major adverse cardiac events included death, myocardial infarction, and urgent revascularization. Costs were calculated on the basis of resource use and Medicare reimbursement rates. Changes in quality-adjusted life-years were assessed with utilities determined by the European Quality of Life-5 Dimensions health survey at baseline and over follow-up. RESULTS: Major adverse cardiac events at 3 years were significantly lower in the PCI group compared with the MT group (10.1% versus 22.0%; P<0.001), primarily as a result of a lower rate of urgent revascularization (4.3% versus 17.2%; P<0.001). Death and myocardial infarction were numerically lower in the PCI group (8.3% versus 10.4%; P=0.28). Angina was significantly less severe in the PCI group at all follow-up points to 3 years. Mean initial costs were higher in the PCI group ($9944 versus $4440; P<0.001) but by 3 years were similar between the 2 groups ($16 792 versus $16 737; P=0.94). The incremental cost-effectiveness ratio for PCI compared with MT was $17 300 per quality-adjusted life-year at 2 years and $1600 per quality-adjusted life-year at 3 years. The above findings were robust in sensitivity analyses. CONCLUSIONS: PCI of lesions with reduced fractional flow reserve improves long-term outcome and is economically attractive compared with MT alone in patients with stable coronary artery disease. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01132495.

Regional layer-specific longitudinal peak systolic strain using exercise stress two-dimensional speckle-tracking echocardiography for the detection of functionally significant coronary artery disease.

The present study aimed to investigate whether layer-specific regional peak-systolic longitudinal strain (LS) measurement on transthoracic echocardiogram (TTE) with exercise stress can be useful for the detection of functionally significant coronary artery disease as confirmed by invasive fractional flow reserve (FFR) in stable patients. This is a prospective analysis of 88 coronary arteries in 30 stable patients undergoing invasive FFR measurement and ergometer exercise stress TTE. Regional LS in the mid, endocardial and epicardial layers was calculated at rest, peak stress and early and late recovery phases after the exercise stress test. The endocardial-to-epicardial LS ratio was calculated as an indicator of endocardial-layer dependency of the left ventricular myocardium. Ischemic FFR defined as FFR ≤ 0.80 was observed in 33 of 88 coronary arteries. The mid-, endocardial- and epicardial-layer LS at early recovery (- 15.4 ± 5.2 vs. - 13.0 ± 4.4%, P = 0.040; - 15.7 ± 5.1 vs. - 13.2 ± 4.5%, P = 0.029; - 14.6 ± 5.1 vs. - 12.4 ± 4.0%, P = 0.038, respectively) and the percent change in the endocardial-to-epicardial LS ratio from baseline to peak stress, early recovery, and late recovery phases (1.5 ± 11.2% vs. 6.6 ± 10.5%, P = 0.009; 2.8 ± 8.9% vs. 7.1 ± 12.6%, P = 0.002; 5.2 ± 8.8% vs. 8.5 ± 13.7%, P = 0.026; respectively) were significantly more impaired in the ischemic territories (FFR ≤ 0.80) compared with the non-ischemic territories (FFR > 0.80). According to the receiver operating characteristic curve analysis, a combination of endocardial LS and percent change in the endocardial-to-epicardial LS ratio at early recovery phase plus visual evaluation of LV wall motion had incremental diagnostic value for the detection of the ischemic territory compared with visual evaluation alone (area under the curve = 0.752 and 0.618, P = 0.006). The results of this study suggested that assessing layer-specific LS and the endocardial-to-epicardial LS ratio after exercise stress on speckle-tracking TTE may have potential for objective and quantitative evaluation in the assessment of myocardial ischemia. Further studies in a larger population are needed to confirm these findings.

Transvaginal cervicoisthmic cerclage for patients with extremely high-risk history of preterm delivery.

Transvaginal cervicoisthmic cerclage was carried out in 12 such patients who were at high-risk of premature delivery. Patients who underwent transvaginal cervicoisthmic cerclage had undergone conization, cervical radical hysterectomy or another form of extensive cervical resection, or had a history of third-trimester miscarriage or premature delivery despite having previously undergone cervical cerclage several times for cervical incompetence. There were seven cases of pregnancy after extensive conization, and four had a history of failed cervical cerclage. Two of these cases were the same individual, who became pregnant twice after extensive conization and gave birth to a live infant each time. The mean age at surgery was 35.7 years, and cerclage was performed at 11-19 weeks' gestation. All of the infants survived to hospital discharge. Transvaginal cervicoisthmic cerclage may be considered effective for patients with the history of recurring pregnancy loss due to previous failure of prophylactic cerclage.

Intravenous nicorandil versus adenosine for fractional flow reserve measurement: a crossover, randomized study.

Nicorandil has vasodilatory effects on both the epicardial coronary arteries and the coronary microvasculature, thereby increasing coronary blood flow. The objective of the present study was to investigate the effectiveness of intravenous (IV) nicorandil infusion for fractional flow reserve (FFR) measurement. In this crossover randomized study, 49 patients underwent FFR measurement with a consecutive randomized order of patient-blind infusions of continuous IV adenosine administration and a single bolus IV administration of nicorandil. The primary endpoint was the difference between the FFR by nicorandil and the FFR by adenosine, as assessed by the Bland-Altman method. The mean FFR value measured by nicorandil was not significantly different from that measured by adenosine [0.8125 ± 0.1349 vs. 0.7978 ± 0.124; mean difference, 0.0147 (95% confidence interval - 0.0373, 0.0667); P = 0.58]. There was no clinically significant diagnostic discordance, with the FFR by nicorandil > 0.80 and that by adenosine < 0.75. Hyperemia was achieved earlier using nicorandil than adenosine (34 ± 13 vs. 58 ± 15, P < 0.001). The duration of hyperemia after IV nicorandil was variable (6-570 s, mean 89 ± 98 s). IV nicorandil decreased systolic blood pressure by 32 ± 16 mm Hg (24 ± 10%) from baseline. Linear regression analysis showed that the average FFR value and the difference in systolic blood pressure were significantly associated with the bias in the FFR value between the two drugs. In conclusions, the results of the present study suggest that IV nicorandil can achieve maximal hyperemia easily and rapidly, providing an acceptable diagnostic performance for FFR assessment. However, a wide range of variation in hyperemic plateau and a decrease in blood pressure are the major limitations of this method.

[Prolonged Survival Following Chemotherapy in Bone Marrow Carcinomatosis Due to Esophagogastric Junctional Carcinoma - A Case Report].

A 60s-year-old Japanese male underwent curative resection for an advanced adenocarcinoma of the esophagogastric junction(Stage III C), followed by adjuvant chemotherapy.Twenty -one months later, he was admitted to our hospital with a complaint of marked decline in activities of daily living(ADL).The patient was diagnosed with pancytopenia, disseminated intravascular coagulation(DIC), multiple lymph node and bone metastases, and bone marrow carcinomatosis.After completing a sufficient informed consent process, he received chemotherapy along with blood transfusion, and then DIC, pancytopenia, and ADL of the patient improved.However, the lack of response of pancytopenia and DIC to transfusion relapsed and his ADL worsened after the second course of chemotherapy.It was difficult to administer additional chemotherapy in the patient and he died 24 months after surgery.There is no established treatment for disseminated carcinomatosis of the bone marrow, and the prognosis of these patients without treatment is reported to be only one month.Our case with prolonged survival following chemotherapy and blood transfusion may support the clinical usefulness of chemotherapy for bone marrow carcinomatosis from esophagogastric junctional carcinoma.

Intraductal papillary mucinous carcinoma of the pancreas associated with pancreas divisum: a case report and review of the literature.

BACKGROUND: Pancreas divisum, the most common congenital anomaly of the pancreas, is caused by failure of the fusion of the ventral and dorsal pancreatic duct systems during embryological development. Although various pancreatic tumors can occur in patients with pancreas divisum, intraductal papillary mucinous neoplasm is rare. CASE PRESENTATION: A 77-year-old woman was referred to our hospital because she was incidentally found to have a cystic tumor in her pancreas at a regular health checkup. Contrast-enhanced abdominal computed tomography images demonstrated a cystic tumor in the head of the pancreas measuring 40 mm in diameter with slightly enhancing mural nodules within the cyst. Endoscopic retrograde pancreatography via the major duodenal papilla revealed a cystic tumor and a slightly dilated main pancreatic duct with an abrupt interruption at the head of the pancreas. The orifice of the major duodenal papilla was remarkably dilated and filled with an abundant extrusion of mucin, and the diagnosis based on pancreatic juice cytology was "highly suspicious for adenocarcinoma". Magnetic resonance cholangiopancreatography depicted a normal, non-dilated dorsal pancreatic duct throughout the pancreas. The patient underwent a pylorus-preserving pancreaticoduodenectomy under the diagnosis of intraductal papillary mucinous neoplasm with suspicion of malignancy arising in the ventral part of the pancreas divisum. A pancreatography via the major and minor duodenal papillae on the surgical specimen revealed that the ventral and dorsal pancreatic ducts were not connected, and the tumor originated in the ventral duct, i.e., the Wirsung's duct. Microscopically, the tumor was diagnosed as intraductal papillary mucinous carcinoma with microinvasion. In addition, marked fibrosis with acinar cell depletion was evident in the ventral pancreas, whereas no fibrotic change was noted in the dorsal pancreas. CONCLUSION: Invasive ductal carcinomas of the pancreas associated with pancreas divisum usually arise from the dorsal pancreas, in which the occurrence of pancreatic cancer may link to underlying longstanding chronic pancreatitis in the dorsal pancreas; however, the histopathogenesis of intraductal papillary mucinous neoplasm in this anomaly is a critical issue that warrants further investigation in future.

Increased platelet inhibition after switching from maintenance clopidogrel to prasugrel in Japanese patients with stable coronary artery disease.

BACKGROUND: The pharmacodynamic effects of changing from standard-dose clopidogrel to low-dose (3.75 mg) prasugrel in Japanese patients are largely unknown. METHODS AND RESULTS: A total of 53 consecutive Japanese patients with stable coronary artery disease (CAD) who received aspirin and clopidogrel were enrolled. Clopidogrel was switched to 3.75 mg prasugrel. At day 14, prasugrel was switched to 75 mg clopidogrel. Platelet reactivity was measured using the VerifyNow assay at baseline, day 14, and day 28. VerifyNow P2Y12 reaction units (PRU) >208 was defined as high on-treatment platelet reactivity (HPR). The prevalence of HPR (18.9% vs. 41.5% vs. 44.2%, P<0.001) and the PRU level (154.3±54.2 vs. 196.2±55.5 vs. 194.6±55.8, P<0.001) were significantly lower on prasugrel maintenance therapy compared with the clopidogrel therapy before and after switching. The CYP2C19 genotypes that account for the 3 phenotypes (ie, extensive metabolizer, intermediate metabolizer, and poor metabolizer) had a significant impact on platelet reactivity with clopidogrel (174.9±54.0 vs. 193.1±56.5 vs. 240.6±25.4 PRU, P<0.001) but not prasugrel (147.0±51.9 vs. 147.5±58.3 vs. 184.4±38.3 PRU, P=0.15). CONCLUSIONS: Low-dose prasugrel achieves stronger platelet inhibition than clopidogrel in Japanese patients with stable CAD.