Dual Antiplatelet Therapy after PCI in Patients at High Bleeding Risk.

BACKGROUND: The appropriate duration of dual antiplatelet therapy in patients at high risk for bleeding after the implantation of a drug-eluting coronary stent remains unclear. METHODS: One month after they had undergone implantation of a biodegradable-polymer sirolimus-eluting coronary stent, we randomly assigned patients at high bleeding risk to discontinue dual antiplatelet therapy immediately (abbreviated therapy) or to continue it for at least 2 additional months (standard therapy). The three ranked primary outcomes were net adverse clinical events (a composite of death from any cause, myocardial infarction, stroke, or major bleeding), major adverse cardiac or cerebral events (a composite of death from any cause, myocardial infarction, or stroke), and major or clinically relevant nonmajor bleeding; cumulative incidences were assessed at 335 days. The first two outcomes were assessed for noninferiority in the per-protocol population, and the third outcome for superiority in the intention-to-treat population. RESULTS: Among the 4434 patients in the per-protocol population, net adverse clinical events occurred in 165 patients (7.5%) in the abbreviated-therapy group and in 172 (7.7%) in the standard-therapy group (difference, -0.23 percentage points; 95% confidence interval [CI], -1.80 to 1.33; P<0.001 for noninferiority). A total of 133 patients (6.1%) in the abbreviated-therapy group and 132 patients (5.9%) in the standard-therapy group had a major adverse cardiac or cerebral event (difference, 0.11 percentage points; 95% CI, -1.29 to 1.51; P = 0.001 for noninferiority). Among the 4579 patients in the intention-to-treat population, major or clinically relevant nonmajor bleeding occurred in 148 patients (6.5%) in the abbreviated-therapy group and in 211 (9.4%) in the standard-therapy group (difference, -2.82 percentage points; 95% CI, -4.40 to -1.24; P<0.001 for superiority). CONCLUSIONS: One month of dual antiplatelet therapy was noninferior to the continuation of therapy for at least 2 additional months with regard to the occurrence of net adverse clinical events and major adverse cardiac or cerebral events; abbreviated therapy also resulted in a lower incidence of major or clinically relevant nonmajor bleeding. (Funded by Terumo; MASTER DAPT ClinicalTrials.gov number, NCT03023020.).

Abbreviated Antiplatelet Therapy in Patients at High Bleeding Risk With or Without Oral Anticoagulant Therapy After Coronary Stenting: An Open-Label, Randomized, Controlled Trial.

BACKGROUND: The optimal duration of antiplatelet therapy (APT) in patients at high bleeding risk with or without oral anticoagulation (OAC) after coronary stenting remains unclear. METHODS: In the investigator-initiated, randomize, open-label MASTER DAPT trial (Management of High Bleeding Risk Patients Post Bioresorbable Polymer Coated Stent Implantation With an Abbreviated Versus Standard DAPT Regimen), 4579 patients at high bleeding risk were randomized after 1-month dual APT to abbreviated or nonabbreviated APT strategies. Randomization was stratified by concomitant OAC indication. In this subgroup analysis, we report outcomes of populations with or without an OAC indication. In the population with an OAC indication, patients changed immediately to single APT for 5 months (abbreviated regimen) or continued ≥2 months of dual APT and single APT thereafter (nonabbreviated regimen). Patients without an OAC indication changed to single APT for 11 months (abbreviated regimen) or continued ≥5 months of dual APT and single APT thereafter (nonabbreviated regimen). Coprimary outcomes at 335 days after randomization were net adverse clinical outcomes (composite of all-cause death, myocardial infarction, stroke, and Bleeding Academic Research Consortium 3 or 5 bleeding events); major adverse cardiac and cerebral events (all-cause death, myocardial infarction, and stroke); and type 2, 3, or 5 Bleeding Academic Research Consortium bleeding. RESULTS: Net adverse clinical outcomes or major adverse cardiac and cerebral events did not differ with abbreviated versus nonabbreviated APT regimens in patients with OAC indication (n=1666; hazard ratio [HR], 0.83 [95% CI, 0.60-1.15]; and HR, 0.88 [95% CI, 0.60-1.30], respectively) or without OAC indication (n=2913; HR, 1.01 [95% CI, 0.77-1.33]; or HR, 1.06 [95% CI, 0.79-1.44]; Pinteraction=0.35 and 0.45, respectively). Bleeding Academic Research Consortium 2, 3, or 5 bleeding did not significantly differ in patients with OAC indication (HR, 0.83 [95% CI, 0.62-1.12]) but was lower with abbreviated APT in patients without OAC indication (HR, 0.55 [95% CI, 0.41-0.74]; Pinteraction=0.057). The difference in bleeding in patients without OAC indication was driven mainly by a reduction in Bleeding Academic Research Consortium 2 bleedings (HR, 0.48 [95% CI, 0.33-0.69]; Pinteraction=0.021). CONCLUSIONS: Rates of net adverse clinical outcomes and major adverse cardiac and cerebral events did not differ with abbreviated APT in patients with high bleeding risk with or without an OAC indication and resulted in lower bleeding rates in patients without an OAC indication. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03023020.

Case report: A novel application of the MicroVascular Plug (MVP) in treating distal coronary perforation.

Coronary artery perforation during percutaneous coronary intervention (PCI) is a rare but severe complication which has been associated with a high rate of major adverse outcomes and is potentially fatal. We report a case of a 70-year-old male who presented with an anterior ST-elevation myocardial infarction. Coronary angiogram revealed a proximal left anterior descending (LAD) artery occlusion. Successful PCI was performed with stenting of the LAD. However, subsequent attempts to retrieve a jailed diagonal branch inadvertently led to distal coronary perforation of the LAD. After failed attempts to tamponade the perforation with prolonged balloon inflation, this was successfully sealed with the MicroVascular Plug (Medtronic) system. To our knowledge, this is the first reported case of such an application in the coronary system. This may prove to be a viable alternative in closure of distal coronary perforations.

Predicting 2-year all-cause mortality after contemporary PCI: Updating the logistic clinical SYNTAX score.

AIMS: We aimed to update the logistic clinical SYNTAX score to predict 2 year all-cause mortality after contemporary percutaneous coronary intervention (PCI). METHODS AND RESULTS: We analyzed 15,883 patients in the GLOBAL LEADERS study who underwent PCI. The logistic clinical SYNTAX model was updated after imputing missing values by refitting the original model (refitted original model) and fitting an extended new model (new model, with, selection based on the Akaike Information Criterion). External validation was performed in 10,100 patients having PCI at Fu Wai hospital. Chronic obstructive pulmonary disease, prior stroke, current smoker, hemoglobin level, and white blood cell count were identified as additional independent predictors of 2 year all-cause mortality and included into the new model. The c-indexes of the original, refitted original and the new model in the derivation cohort were 0.74 (95% CI 0.72-0.76), 0.75 (95% CI 0.73-0.77), and 0.78 (95% CI 0.76-0.80), respectively. The c-index of the new model was lower in the validation cohort than in the derivation cohort, but still showed improved discriminative ability of the newly developed model (0.72; 95% CI 0.67-0.77) compared to the refitted original model (0.69; 95% CI 0.64-0.74). The models overestimated the observed 2 year all-cause mortality of 1.11% in the Chinese external validation cohort by 0.54 percentage points, indicating the need for calibration of the model to the Chinese patient population. CONCLUSIONS: The new model of the logistic clinical SYNTAX score better predicts 2 year all-cause mortality after PCI than the original model. The new model could guide clinical decision making by risk stratifying patients undergoing PCI.

Fractional Flow Reserve-Guided Multivessel Angioplasty in Myocardial Infarction.

BACKGROUND: In patients with ST-segment elevation myocardial infarction (STEMI), the use of percutaneous coronary intervention (PCI) to restore blood flow in an infarct-related coronary artery improves outcomes. The use of PCI in non-infarct-related coronary arteries remains controversial. METHODS: We randomly assigned 885 patients with STEMI and multivessel disease who had undergone primary PCI of an infarct-related coronary artery in a 1:2 ratio to undergo complete revascularization of non-infarct-related coronary arteries guided by fractional flow reserve (FFR) (295 patients) or to undergo no revascularization of non-infarct-related coronary arteries (590 patients). The FFR procedure was performed in both groups, but in the latter group, both the patients and their cardiologist were unaware of the findings on FFR. The primary end point was a composite of death from any cause, nonfatal myocardial infarction, revascularization, and cerebrovascular events at 12 months. Clinically indicated elective revascularizations performed within 45 days after primary PCI were not counted as events in the group receiving PCI for an infarct-related coronary artery only. RESULTS: The primary outcome occurred in 23 patients in the complete-revascularization group and in 121 patients in the infarct-artery-only group that did not receive complete revascularization, a finding that translates to 8 and 21 events per 100 patients, respectively (hazard ratio, 0.35; 95% confidence interval [CI], 0.22 to 0.55; P<0.001). Death occurred in 4 patients in the complete-revascularization group and in 10 patients in the infarct-artery-only group (1.4% vs. 1.7%) (hazard ratio, 0.80; 95% CI, 0.25 to 2.56), myocardial infarction in 7 and 28 patients, respectively (2.4% vs. 4.7%) (hazard ratio, 0.50; 95% CI, 0.22 to 1.13), revascularization in 18 and 103 patients (6.1% vs. 17.5%) (hazard ratio, 0.32; 95% CI, 0.20 to 0.54), and cerebrovascular events in 0 and 4 patients (0 vs. 0.7%). An FFR-related serious adverse event occurred in 2 patients (both in the group receiving infarct-related treatment only). CONCLUSIONS: In patients with STEMI and multivessel disease who underwent primary PCI of an infarct-related artery, the addition of FFR-guided complete revascularization of non-infarct-related arteries in the acute setting resulted in a risk of a composite cardiovascular outcome that was lower than the risk among those who were treated for the infarct-related artery only. This finding was mainly supported by a reduction in subsequent revascularizations. (Funded by Maasstad Cardiovascular Research and others; Compare-Acute ClinicalTrials.gov number, NCT01399736 .).

Design and rationale of the Management of High Bleeding Risk Patients Post Bioresorbable Polymer Coated Stent Implantation With an Abbreviated Versus Standard DAPT Regimen (MASTER DAPT) Study.

BACKGROUND: The optimal duration of antiplatelet therapy in high-bleeding risk (HBR) patients with coronary artery disease treated with newer-generation drug-eluting bioresorbable polymer-coated stents remains unclear. DESIGN: MASTER DAPT (clinicaltrial.govNCT03023020) is an investigator-initiated, open-label, multicenter, randomized controlled trial comparing an abbreviated versus a standard duration of antiplatelet therapy after bioresorbable polymer-coated Ultimaster (TANSEI) sirolimus-eluting stent implantation in approximately 4,300 HBR patients recruited from ≥100 interventional cardiology centers globally. After a mandatory 30-day dual-antiplatelet therapy (DAPT) run-in phase, patients are randomized to (a) a single antiplatelet regimen until study completion or up to 5 months in patients with clinically indicated oral anticoagulation (experimental 1-month DAPT group) or (b) continue DAPT for at least 5 months in patients without or 2 in patients with concomitant indication to oral anticoagulation, followed by a single antiplatelet regimen (standard antiplatelet regimen). With a final sample size of 4,300 patients, this study is powered to assess the noninferiority of the abbreviated antiplatelet regimen with respect to the net adverse clinical and major adverse cardiac and cerebral events composite end points and if satisfied for the superiority of abbreviated as compared to standard antiplatelet therapy duration in terms of major or clinically relevant nonmajor bleeding. Study end points will be adjudicated by a blinded Clinical Events Committee. CONCLUSIONS: The MASTER DAPT study is the first randomized controlled trial aiming at ascertaining the optimal duration of antiplatelet therapy in HBR patients treated with sirolimus-eluting bioresorbable polymer-coated stent implantation.

Biolimus-A9 polymer-free coated stent in high bleeding risk patients with acute coronary syndrome: a Leaders Free ACS sub-study.

Aims: Although a true clinical challenge, high bleeding risk patients with an acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) have never been specifically studied. Leaders Free ACS, a pre-specified Leaders Free sub-study, determined efficacy, and safety of a combination of 1-month dual anti-platelet therapy (DAPT) with implantation of either a polymer-free Biolimus-A9-coated stent (BA9-DCS) or a bare-metal stent (BMS) in these patients. Methods and results: Leaders Free included 2466 patients undergoing PCI who had at least 1 of 13 pre-defined factors for an increased bleeding risk. Of these, 659 ACS patients were included in this analysis (BA9-DCS 330, BMS 329). At 12-month follow-up, treatment with the BA9-DCS was more effective (clinically driven target-lesion revascularization 3.9 vs. 9.0%, P = 0.009) and safer (cumulative incidence of cardiac death, myocardial infarction, or definite or probable stent thrombosis 9.3 vs. 18.5%, P = 0.001), driven by significantly lower rates of cardiac mortality (3.4 vs. 6.9%, P = 0.049) and myocardial infarction (6.9 vs. 13.8%, P = 0.005). Conclusion: We believe that the results of this sub-analysis from the Leaders Free trial are likely to significantly impact clinical practice for high bleeding risk patients presenting with an ACS: the use of a BMS can, in our view, no longer be recommended, and, given the paucity of available data for second-generation DES with shortened DAPT in these patients, the BA9-DCS should currently be considered as the device with the strongest evidence to support its use for this indication.

Drug-Coated Balloons: A Safe and Effective Alternative to Drug-Eluting Stents in Small Vessel Coronary Artery Disease.

BACKGROUND: Drug-coated balloons (DCB) have been used to treat de novo small vessel coronary disease (SVD), with promising results and shorter dual antiplatelet therapy (DAPT) duration compared to drug-eluting stents (DES). We compared safety and effectiveness of the two treatments at 1 year. METHODS: We reviewed 3,613 angioplasty cases retrospectively from 2011 to 2013 and identified 335 patients with SVD treated with device diameter of ≤2.5 mm. DCB-only angioplasty was performed in 172 patients, whereas 163 patients were treated with second-generation DES. RESULTS: DCB patients had smaller reference vessel diameter (2.22 ± 0.30 vs. 2.44 ± 0.19 mm, P < 0.001) and received smaller devices (median diameter 2.25 vs. 2.50 mm, P < 0.001) compared to the DES group. DES-treated vessels had larger acute lumen gain (1.71 ± 0.48 mm) than DCB (1.00 ± 0.53 mm, P < 0.001). Half the patients had diabetes mellitus. While there were more patients presenting with acute coronary syndrome (ACS) in the DCB group (77.9% vs. 62.2%, P = 0.013), they received shorter DAPT (7.4 ± 4.7 vs. 11.8 ± 1.4 months, P < 0.001) than the DES group. The 1-year composite major adverse cardiac event rate was 11.6% in the DCB arm and 11.7% in the DES arm (P = 1.000), with target lesion revascularization rate of 5.2% and 3.7%, respectively, (P = 0.601). CONCLUSIONS: In this high-risk cohort of patients, DCB-only angioplasty delivered good clinical outcome at 1 year. The results were comparable with DES-treated patients, but had the added benefit of a shorter DAPT regime.

Abbreviated Antiplatelet Therapy After Coronary Stenting in Patients With Myocardial Infarction at High Bleeding Risk.

BACKGROUND: The optimal duration of antiplatelet therapy (APT) after coronary stenting in patients at high bleeding risk (HBR) presenting with an acute coronary syndrome remains unclear. OBJECTIVES: The objective of this study was to investigate the safety and efficacy of an abbreviated APT regimen after coronary stenting in an HBR population presenting with acute or recent myocardial infarction. METHODS: In the MASTER DAPT trial, 4,579 patients at HBR were randomized after 1 month of dual APT (DAPT) to abbreviated (DAPT stopped and 11 months single APT or 5 months in patients with oral anticoagulants) or nonabbreviated APT (DAPT for minimum 3 months) strategies. Randomization was stratified by acute or recent myocardial infarction at index procedure. Coprimary outcomes at 335 days after randomization were net adverse clinical outcomes events (NACE); major adverse cardiac and cerebral events (MACCE); and type 2, 3, or 5 Bleeding Academic Research Consortium bleeding. RESULTS: NACE and MACCE did not differ with abbreviated vs nonabbreviated APT regimens in patients with an acute or recent myocardial infarction (n = 1,780; HR: 0.83; 95% CI: 0.61-1.12 and HR: 0.86; 95% CI: 0.62-1.19, respectively) or without an acute or recent myocardial infarction (n = 2,799; HR: 1.03; 95% CI: 0.77-1.38 and HR: 1.13; 95% CI: 0.80-1.59; Pinteraction = 0.31 and 0.25, respectively). Bleeding Academic Research Consortium 2, 3, or 5 bleeding was significantly reduced in patients with or without an acute or recent myocardial infarction (HR: 0.65; 95% CI: 0.46-0.91 and HR: 0.71; 95% CI: 0.54-0.92; Pinteraction = 0.72) with abbreviated APT. CONCLUSIONS: A 1-month DAPT strategy in patients with HBR presenting with an acute or recent myocardial infarction results in similar NACE and MACCE rates and reduces bleedings compared with a nonabbreviated DAPT strategy. (Management of High Bleeding Risk Patients Post Bioresorbable Polymer Coated Stent Implantation With an Abbreviated Versus Prolonged DAPT Regimen [MASTER DAPT]; NCT03023020).

2021 Asian Pacific Society of Cardiology Consensus Recommendations on the Use of P2Y12 Receptor Antagonists in the Asia-Pacific Region: Special Populations.

Advanced age, diabetes, and chronic kidney disease not only increase the risk for ischaemic events in chronic coronary syndromes (CCS) but also confer a high bleeding risk during antiplatelet therapy. These special populations may warrant modification of therapy, especially among Asians, who have displayed characteristics that are clinically distinct from Western patients. Previous guidance has been provided regarding the classification of high-risk CCS and the use of newer-generation P2Y12 inhibitors (i.e. ticagrelor and prasugrel) after acute coronary syndromes (ACS) in Asia. The authors summarise evidence on the use of these P2Y12 inhibitors during the transition from ACS to CCS and among special populations. Specifically, they present recommendations on the roles of standard dual antiplatelet therapy, shortened dual antiplatelet therapy and single antiplatelet therapy among patients with coronary artery disease, who are either transitioning from ACS to CCS; elderly; or with chronic kidney disease, diabetes, multivessel coronary artery disease and bleeding events during therapy.

Drug-Coated Balloons for Coronary Artery Disease: Third Report of the International DCB Consensus Group.

Although drug-eluting stents are still the default interventional treatment of coronary artery disease, drug-coated balloons (DCBs) represent a novel alternative therapeutic strategy in certain anatomic conditions. The effect of DCBs is based on the fast and homogenous transfer of antiproliferative drugs into the vessel wall during single balloon inflation by means of a lipophilic matrix without the use of permanent implants. Although their use is established for in-stent restenosis of both bare-metal and drug-eluting stents, recent randomized clinical data demonstrate a good efficacy and safety profile in de novo small-vessel disease and high bleeding risk. In addition, there are other emerging indications (e.g., bifurcation lesions, large-vessel disease, diabetes mellitus, acute coronary syndromes). Because the interaction among the different delivery balloon designs, doses, formulations, and release kinetics of the drugs used is important, there seems to be no "class effect" of DCBs. On the basis of the amount of recently published data, the International DCB Consensus Group provides this update of previous recommendations summarizing the historical background, technical considerations such as choice of device and implantation technique, possible indications, and future perspectives.

Angiographic, optical coherence tomography and histology findings from combination of a drug-coated balloon with an everolimus-eluting stent in a porcine model.

BACKGROUND: We designed a porcine model to compare the angiographic, optical coherence tomography (OCT) and histological findings of implanting an everolimus-eluting stent (EES) in the same segment of the coronary artery pre-treated with a drug-coating balloon (DCB; paccocath as carrier) with EES alone and DCB plus a bare metal stent (BMS). METHODS: Seven female swine averaging 46.0±2.4kg were treated by random assignment as follows: DCB followed by EES; DCB followed by BMS; and EES alone. Quantitative coronary angiography (QCA) and OCT were carried out post-implantation and repeated after 28±1days. RESULTS: All arteries remained patent and demonstrated no sign of thrombus formation. There was no significant difference at 1month between the treatment groups in lumen loss (0.64±0.43, 0.44±0.43 and 0.33±0.28mm for EES, DCB/EES and DCB/BMS respectively, p=0.37) and binary restenosis (6.86 (2.91-9.12), 4.93 (-1.53-10.7) and 4.18 (3.27-10.2)% respectively, p=0.87). OCT found mean neointimal thickness of 0.15±0.09, 0.07±0.03 and 0.08±0.03mm (p=0.05) for EES, DCB/EES and DCB/BMS respectively. Endothelial strut coverage was 92.3±5.5, 85.4±8.6 and 89.1±8.9% (p=0.05) and mean neointimal area was 1.06±0.42, 0.95±0.24 and 1.20±0.28mm2 (p=0.09) respectively. Inflammation score was similar between the three groups: 0.20 (0.20-0.28), 0.30 (0.22-0.48), 0.30 (0.20-0.38) for EES, DCB/EES and DCB/BMS respectively (p=0.14) and there were no differences in fibrin deposition. CONCLUSIONS: The combination of DCB with EES appeared to be safe and effective. Using EES to bail out suboptimal DCB therapy appeared to be safe and effective in this porcine model.

Long-term use of contraceptive depot medroxyprogesterone acetate in young women impairs arterial endothelial function assessed by cardiovascular magnetic resonance.

BACKGROUND: Depot medroxyprogesterone acetate (DMPA) inhibits proliferation of ovarian follicles, resulting in anovulation and a decrease in circulating estrogen; the latter action is potentially disadvantageous to cardiovascular health. We therefore investigated the vascular effects of long-term contraceptive DMPA in young women. METHODS AND RESULTS: Endothelium-dependent (hyperemia-induced flow-mediated dilatation [FMD]) and -independent (glyceryl trinitrate [GTN]) changes in brachial artery area were measured using cardiovascular magnetic resonance in 13 amenorrheic DMPA users (>1 year use; mean age 29+/-4 years) and in 10 controls (mean age 30+/-4 years, P=0.25) with regular menstrual cycles after validation of the technique. FMD and GTN responses were measured just before repeat MPA injection and 48 hours later (n=12) in DMPA users and during menstruation and midcycle (n=9) in controls. Serum-estradiol levels (S-estradiol) were measured at both visits. FMD was reduced in DMPA users compared with controls during menstruation (1.1% versus 8.0%, respectively P<0.01) without differences in GTN responses. S-estradiol levels in DMPA users were significantly lower than in controls during menstruation (58 versus 96 pmol/L, P<0.01). High levels of circulating MPA 48 hours after injection were not linked to an additional impairment in FMD (2.0% versus 3.1%, P=0.23). Estradiol levels were significantly correlated to FMD (r=0.43, P<0.01). CONCLUSIONS: Endothelium-dependent arterial function measured by cardiovascular magnetic resonance is impaired in chronic users of DMPA, and hypoestrogenism may be the mechanism of action. DMPA might adversely affect cardiovascular health, and in particular its use in women with cardiovascular disease should be additionally evaluated.

Drug coated balloon angioplasty in elderly patients with small vessel coronary disease.

BACKGROUND: Coronary angioplasty in advanced age is associated with higher rate of comorbidities and complications. Drug coated balloon only angioplasty (DCBA) has emerged as an alternative to treat small vessel coronary disease (SVCD), of reference vessel diameters <2.8 mm, with shorter duration of dual antiplatelet (DAPT). This is the first study to assess the DCBA efficacy in an elderly population with SVCD. METHODS AND RESULTS: We performed a prospective study of 447 patients (334 patients aged <75 and 113 patients aged ⩾75 years old) acquired from the SeQuent Please Small Vessel 'Paclitaxel-Coated Balloon Only' registry. In the older age group, more patients have hypertension (89% versus 77%; p = 0.006), renal insufficiency (21% versus 6%; p < 0.001), atrial fibrillation (17% versus 7%; p = 0.001), and calcified lesions (33% versus 20%; p = 0.006). At 30 days, there was one myocardial infarction requiring target lesion revascularization (TLR) in the younger group. No major adverse cardiac event (MACE) was observed in the older group. At 9 months, the MACE rate in the younger group was 4.2% and 6.1% in the older group (p = 0.453), with TLR rates at 3.9% and 3.0% (p = 0.704) respectively. There was no cardiac death observed. CONCLUSION: DBCA in the elderly with SVCD is as safe and effective compared with younger patients despite more complex anatomy and comorbidities.

Effects of hydrostatic distention on in vitro vasoreactivity of radial artery conduits.

BACKGROUND: Surgical preparation of coronary conduits may affect early and long-term patency through endothelial and smooth muscle injury. We investigated the effect of hydrostatic distention on the in vitro endothelial function and contractile properties of the human radial artery. METHODS: Human radial arteries were harvested and distended to physiologic pressure or suprasystemic pressure (>300 mm Hg) by using heparinized whole blood for 2 minutes. Distal segments were retrieved and prepared into 3-mm rings. These were mounted and stretched to optimum resting tension in oxygenated Krebs solution at 37 degrees C. Contraction responses to potassium, norepinephrine, and serotonin and relaxation responses to acetylcholine and nitroprusside were evaluated. Undistended radial artery segments were used as controls. RESULTS: Vasocontraction to all 3 contractile agonists was significantly different between groups. The radial artery subjected to suprasystemic pressure distention achieved the lowest percentage of maximum contraction (potassium, P <.001; norepinephrine, P <.05; serotonin, P <.05). The median effective concentration was also significantly reduced in this group, indicating increased sensitivity to all 3 agonists. Receptor-mediated contractility was significantly reduced in both distended groups when compared with controls. Relaxation to acetylcholine and nitroprusside was significantly reduced in the suprasystemic pressure-distended group, which had a tendency to vasospasm when exposed to a physiologic concentration of acetylcholine (10(-6) mol/L). Median effective concentrations for both acetylcholine and nitroprusside were not different between groups. CONCLUSIONS: Excessive distention of the radial artery leads to a significant reduction in vasoreactivity, which may be attributed to a disruption of the vascular endothelium and media, with a propensity for graft spasm with exposure to acetylcholine.

Effects of radial artery harvesting on forearm function and blood flow.

BACKGROUND: There is little information on the effects of radial artery harvesting on postoperative forearm function and blood flow. We evaluated the early changes in forearm neural sensation, circumference, grip power, cyclical exercise fatigue, and blood flow after radial artery harvesting for coronary artery bypass graft (CABG) surgery. METHODS: Twenty-three patients with negative Allen's test of the nondominant forearm were recruited preoperatively and underwent assessment of bilateral forearm function (soft touch and pin-prick neural sensation, circumference, handgrip power, cyclical exercise fatigue) and blood flow measurements (forearm plethysmography). All vasoactive drugs were stopped 24 hours before assessments. Identical follow-up assessments were conducted (mean +/- SEM) 3.4 +/- 0.4 months postoperatively. RESULTS: At the time of postoperative assessment all harvested forearm wounds were healed. There was no reduction of postoperative soft touch sensation but in 3 patients objective pinprick sensation was reduced in the distribution of the lateral antebrachial cutaneous nerve of the harvested forearms. Postoperative forearm circumference (p < 0.05) and grip power (p < 0.05) were significantly reduced in both forearms, however cyclical exercise fatigue was improved in both forearms. Preoperative and postoperative forearm blood flow at rest and in exercise-induced ischemic reperfusion were not significantly different in both forearms. CONCLUSIONS: In patients with a negative Allen's test, harvesting of the radial artery does not adversely affect subsequent forearm function or blood flow to a clinically significant degree.

A comparison of brachial artery reactivity measured by external and intravascular ultrasound.

External ultrasound (US), EXUS, is widely used to measure brachial artery (BA) diameter changes in the assessment of vascular function; however, it has not been compared with other imaging modalities. We simultaneously measured BA diameter responses to hyperaemic flow and nitrate using EXUS and intravascular ultrasound (US), IVUS, in 10 patients. Mean diameters measured across all time periods correlated closely (r = 0.67, p < 0.001). Percent diameter change to hyperaemia and nitrate also correlated well (r = 0.67, p < 0.01). IVUS cross-sectional area (CSA) was significantly different from that calculated from EXUS using pir(2) (23.95 +/- 4.89 vs. 20.35 +/- 4.51 mm(2), respectively, p < 0.001). Orthogonal diameters measured by IVUS were significantly different (5.45 +/- 0.85 vs. 5.17 +/- 0.79 mm, respectively, p < 0.005). In conclusion, EXUS and IVUS BA diameter measurements correlated well; however, discrepancies in absolute measurements were revealed. The cross-section of the BA is oval; therefore, deriving CSA by pir(2) is inaccurate.

Rheolytic thrombectomy in patients with massive pulmonary embolism: a report of two cases and review of literature.

We present two cases of massive pulmonary embolism with persistent systolic hypotension but both have contraindications for thrombolysis. Therefore, rheolytic thrombectomy using AngioJet was performed and immediate haemodynamic improvement was achieved including blood pressure and symptoms. According to guidelines, catheter embolectomy or fragmentation may be considered as alternative to surgical treatment in massive pulmonary embolism patients when thrombolysis is absolutely contraindicated or has failed. Percutaneous catheter-based interventional techniques include thrombus fragmentation, rheolytic thrombectomy, suction thrombectomy and rotational thrombectomy. With the existing literature review and our case, rheolytic thrombectomy for treatment of massive pulmonary embolism using AngioJet achieves a high procedural success rate (approximately 90%) n terms of improvement of haemodynamics, pulmonary perfusion and angiographic result but low complication rate.