Smoking and outcomes following guided de-escalation of antiplatelet treatment in acute coronary syndrome patients: a substudy from the randomized TROPICAL-ACS trial.

AIMS: Prior analyses disclosed variations in antiplatelet drug response and clinical outcomes between smokers and non-smokers, thus the safety and efficacy of any dual antiplatelet therapy (DAPT) de-escalation strategy may differ in relation to smoking status. Hence, we assessed the impact of smoking on clinical outcomes and adenosine diphosphate-induced platelet aggregation following guided de-escalation of DAPT in invasively managed acute coronary syndrome (ACS) patients. METHODS AND RESULTS: The multicentre TROPICAL-ACS trial randomized 2610 biomarker-positive ACS patients 1:1 to standard treatment with prasugrel for 12 months (control group) or a platelet function testing guided de-escalation of DAPT. Current smokers (n = 1182) showed comparable event rates between study groups [6.6% vs. 6.6%; hazard ratio (HR) 1.0, 95% confidence interval (CI) 0.64-1.56, P > 0.99]. In non-smokers (n = 1428), a guided DAPT de-escalation was associated with a lower 1-year incidence of the primary endpoint [cardiovascular death, myocardial infarction, stroke, or bleeding ≥ Grade 2 according to Bleeding Academic Research Consortium (BARC) criteria] compared with control group patients (7.9% vs. 11.0%; HR 0.71, 95% CI 0.50-0.99, P = 0.048). This reduction was mainly driven by a lower rate of BARC ≥ Grade 2 bleedings (5.2% vs. 7.7%; HR 0.68, 95% CI 0.45-1.03, P = 0.066). There was no significant interaction of smoking status with treatment effects of guided DAPT de-escalation (Pint = 0.23). Adenosine diphosphate-induced platelet aggregation values were higher in current smokers [median 28 U, interquartile range (IQR: 20-40)] vs. non-smoker [median 24 U (16-25), P < 0.0001] in the control group and in current smokers [median 42 U, IQR (27-68)] vs. non-smoker [median 37 U, IQR (25-55), P < 0.001] in the monitoring group. CONCLUSION: Guided DAPT de-escalation appears to be equally safe and effective in smokers and non-smokers. Regardless of smoking status and especially for those patients deemed unsuitable for 1 year of potent platelet inhibition this DAPT strategy might be used as an alternative antiplatelet treatment regimen.

Gender and Outcomes following Guided De-Escalation of Antiplatelet Treatment in Acute Coronary Syndrome Patients: The TROPICAL-ACS Gender Substudy.

OBJECTIVES: This prespecified analysis of the TROPICAL-ACS trial aimed to assess the impact of gender on clinical outcomes and platelet reactivity (PR) following guided de-escalation of dual antiplatelet treatment (DAPT) in acute coronary syndrome (ACS) patients. BACKGROUND: Guided de-escalation of DAPT was recently identified as an effective alternative treatment strategy in ACS. METHODS: We used Cox proportional hazards models and linear regression analysis to assess the interaction of gender with clinical endpoints and PR. RESULTS: In both male (n = 2,052) and female (n = 558) patients, the 1-year incidence of the primary endpoint did not differ in guided de-escalation versus control group patients (male: 7.0% vs. 9.0%; hazard ratio [HR], 0.78, 95% confidence interval [CI], 0.57-1.06, p = 0.11; female: 8.4% vs. 9.2%; HR, 0.92, 95% CI, 0.53-1.62, p = 0.76, p int = 0.60). The 1-year incidence of combined ischemic events (male: 2.5% vs. 3.3%; HR, 0.76, 95% CI, 0.46-1.26, p = 0.29; female: 2.2% vs. 2.8%; HR, 0.78,95% CI, 0.27-2.25, p = 0.65, p int = 0.96) as well as Bleeding Academic Research Consortium ≥ 2 bleeding (male: 4.6% vs. 6.0%; HR, 0.77, 95% CI, 0.52-1.12, p = 0.17; female: 6.2% vs. 6.4%; HR, 0.99, 95% CI, 0.51-1.92, p = 0.97, p int = 0.51) was similar in the guided de-escalation versus control group for both male and female patients. Interaction testing revealed no significant impact of gender on PR levels (prasugrel or clopidogrel) across treatment groups (p int = 0.72). CONCLUSION: Guided de-escalation of DAPT appears to be equally safe and effective in women and men. Especially in patients with increased bleeding risk and independent from gender, a guided DAPT de-escalation strategy may be used as an alternative treatment strategy. CLINICAL TRIAL REGISTRATION: URL: https//www.clinicaltrials.gov. Unique Identifier: NCT: 01959451.

Diabetes and outcomes following guided de-escalation of antiplatelet treatment in acute coronary syndrome patients undergoing percutaneous coronary intervention: a pre-specified analysis from the randomised TROPICAL-ACS trial.

AIMS: A guided de-escalation of P2Y12 inhibitor treatment is considered an alternative treatment strategy in ACS patients undergoing PCI. However, the safety and efficacy of this strategy may differ in diabetic vs non-diabetic patients. The aim of this study was to compare the outcomes of platelet function testing (PFT)-guided de-escalation of dual antiplatelet therapy (DAPT) in ACS patients with and without diabetes mellitus. METHODS AND RESULTS: The TROPICAL-ACS trial randomised 2,610 biomarker-positive ACS patients 1:1 to either standard treatment with prasugrel for 12 months (control group) or PFT-guided DAPT de-escalation. The association and interaction of diabetes on clinical endpoints across treatment groups and on platelet reactivity was investigated. In diabetic patients (n=527, 20.2%), the overall event rates were high and the one-year incidence of the primary endpoint (cardiovascular death, myocardial infarction, stroke or bleeding ≥grade 2) did not differ between guided de-escalation and control group patients (12.5% vs 10.8%; HR 1.17, 95% CI: 0.71-1.93, p=0.55). In non-diabetic patients (n=2,083, 79.8%), the one-year incidence of the primary endpoint was lower in the guided de-escalation vs control group (6.1% vs 8.5%; HR 0.71, 95% CI: 0.52-0.99, p=0.04, pint=0.10). Diabetic patients showed higher platelet reactivity levels in both control (=on prasugrel, p=0.01) and guided de-escalation group (=on clopidogrel, p=0.005) patients. CONCLUSIONS: Although diabetic status did not significantly interfere with the treatment effects of guided DAPT de-escalation, our results suggest that this approach might be safe and effective in non-diabetic patients. Further investigation is definitely warranted in diabetic patients.

Genotype-Phenotype Association and Impact on Outcomes following Guided De-Escalation of Anti-Platelet Treatment in Acute Coronary Syndrome Patients: The TROPICAL-ACS Genotyping Substudy.

BACKGROUND: Phenotype-guided de-escalation (PGDE) of P2Y12-inhibitor treatment with an early switch from prasugrel to clopidogrel was identified as an effective alternative treatment strategy in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). The Testing Responsiveness to Platelet Inhibition on Chronic Antiplatelet Treatment for Acute Coronary Syndromes (TROPICAL-ACS) Genotyping Substudy aimed to investigate whether CYP2C19 genotypes correlate with on-treatment platelet reactivity (PR) in ACS patients treated with clopidogrel or prasugrel and thus might be useful for guidance of early de-escalation of anti-platelet treatment. METHODS AND RESULTS: A total of 603 ACS consecutive patients were enrolled in four centres (23.1% of the overall TROPICAL-ACS population). Rapid genotyping (Spartan RX) for CYP2C19*2, *3 and *17 alleles was performed. Associations between PR and the primary and secondary endpoints of the TROPICAL-ACS trial and CYP2C19*2 and CYP2C19*17 carrier status were evaluated.For the PGDE group, the on-clopidogrel PR significantly differed across CYP2C19*2 (p < 0.001) and CYP2C19*17 genotypes (p = 0.05). Control group patients were not related (p = 0.90, p = 0.74) to on-prasugrel PR. For high PR versus non-high PR patients within the PGDE group, significant differences were observed for the rate of CYP2C19*2 allele carriers (43% vs. 28%, p = 0.007). CONCLUSION: CYP2C19*2 and CYP2C19*17 carrier status correlates with PR in ACS patients treated with clopidogrel and thus might be useful for pre-selecting patients who will and who may not be suitable for PGDE of anti-platelet treatment. Regarding phenotype-guided treatment, we did not observe added benefit of genotyping to predict ischaemic and bleeding risk in patients who underwent a PGDE approach. CLINICAL TRIAL REGISTRATION: URL: https//www.clinicaltrials.gov. Unique Identifier: NCT: 01959451.

Deceleration Capacity of Heart Rate After Acute Altitude Exposure.

Hamm, Wolfgang, Lukas von Stülpnagel, Mathias Klemm, Monika Baylacher, Konstantinos D. Rizas, Axel Bauer, and Stefan Brunner. Deceleration capacity of heart rate after acute altitude exposure. High Alt Med Biol 19:299-302, 2018. BACKGROUND: The autonomic nervous system plays a crucial role in adaptive changes after high-altitude exposure. Deceleration capacity (DC) of heart rate is an advanced marker of heart rate variability (HRV) that predominantly reflects the vagal activity of the cardiac autonomic nervous system. The impact of high-altitude exposure on DC has not been investigated yet. METHODS: In eight healthy individuals we performed a high-resolution digital 30-min electrocardiography in Frank leads configuration at baseline (521 m altitude), immediately after ascent to the Environmental Research Station Schneefernerhaus (UFS) at Zugspitze (2650 m altitude) and after a sojourn of 24 hours at this altitude. DC of heart rate was assessed using customized software. In addition, standard parameters of HRV were assessed. RESULTS: DC decreased significantly from 10.2 ± 0.8 ms to 8.9 ± 1.0 ms (p < 0.05) after acute altitude exposure. After a sojourn of 24 hours at high altitude, DC remained low at 8.6 ± 1.2 ms. There were no significant changes in standard parameters of HRV. CONCLUSION: Our findings show for the first time a decrease of DC of heart rate providing a novel insight into the dysbalance of autonomic nervous system at high altitude.

Age and outcomes following guided de-escalation of antiplatelet treatment in acute coronary syndrome patients undergoing percutaneous coronary intervention: results from the randomized TROPICAL-ACS trial.

Aims: Guided de-escalation of P2Y12-inhibitor treatment was recently identified as an effective alternative treatment strategy in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention. Safety and efficacy of this strategy may differ in relation to patient's age. This pre-specified analysis of the TROPICAL-ACS trial aimed to assess the impact of age on clinical outcomes following guided de-escalation of antiplatelet treatment in ACS patients. Methods and results: Patients were randomly assigned in a 1:1 fashion to either standard treatment with prasugrel for 12 months (control group) or to a guided de-escalation regimen (1 week prasugrel followed by 1 week clopidogrel and platelet function testing guided maintenance therapy with clopidogrel or prasugrel from day 14 after hospital discharge; guided de-escalation group). We used Cox regression models to assess the associations of age on clinical endpoints and interactions. In younger patients (age ≤70, n = 2240), the 1 year incidence of the primary endpoint (cardiovascular death, myocardial infarction, stroke, or bleeding ≥ grade 2 according to Bleeding Academic Research Consortium criteria) was significantly lower in guided de-escalation vs. control group [5.9% vs. 8.3%; hazard ratio (HR) 0.70, 95% confidence interval (CI) 0.51-0.96; P = 0.03, number needed to treat = 42]. In elderly patients (age >70, n = 370), the absolute risk of events was higher without significant differences between guided de-escalation vs. control group (15.5% vs. 13.6%; HR 1.17, 95% CI 0.69-2.01; P = 0.56). When the impact of age, as a continuous variable, was analysed on outcomes after guided de-escalation vs. control treatment, an increasing relative risk reduction was observed in the primary endpoint by decreasing age (Pint = 0.02), due to significant reductions in bleeding. Conclusion: Treatment effects of guided de-escalation for P2Y12 inhibitors depend on patient's age with younger patients deriving a significant net clinical benefit. Although the safety and efficacy of guided de-escalation in the elderly was similar to uniform prasugrel therapy, this should be further investigated due to the limited sample size of this group.

A randomised trial on platelet function-guided de-escalation of antiplatelet treatment in ACS patients undergoing PCI. Rationale and design of the Testing Responsiveness to Platelet Inhibition on Chronic Antiplatelet Treatment for Acute Coronary Syndromes (TROPICAL-ACS) Trial.

Outcomes of acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) have been significantly improved with the use of potent P2Y12 receptor inhibitors like prasugrel. While most of the ischaemic risk reduction for prasugrel versus clopidogrel was demonstrated in the early treatment period, the risk of bleeding became particularly prominent during the chronic course of therapy. It may therefore be a valid approach to substitute prasugrel for clopidogrel in the early phase of chronic antiplatelet treatment after PCI. In the Testing Responsiveness To Platelet Inhibition On Chronic Antiplatelet Treatment For Acute Coronary Syndromes (TROPICAL-ACS) trial, we aim to compare standard prasugrel therapy with a de-escalating antiplatelet treatment approach guided by platelet function testing (PFT). The study is an investigator-initiated European multicentre, randomised clinical trial in biomarker-positive ACS patients after successful PCI. Two thousand six hundred patients will be randomised prior to hospital discharge in a 1:1 fashion to either receive standard prasugrel therapy (control group) or de-escalating therapy (one-week prasugrel followed by one-week clopidogrel and PFT-guided maintenance therapy from day 14 after hospital discharge, monitoring group). Patients of the monitoring group with high on-clopidogrel platelet reactivity (HPR) based on Multiplate analyzer testing (HPR: ≥ 46U per consensus definition) will be switched back to prasugrel, whereas those without HPR (<46 U) will continue clopidogrel treatment. The overall study treatment duration will be one year in both groups. The primary endpoint of the study is net clinical benefit (combined incidence of cardiovascular death, myocardial infarction, stroke and bleeding ≥ grade 2 according to BARC criteria) one-year after randomisation. TROPICAL-ACS is the first large-scale, randomised controlled trial assessing the clinical value of a PFT-guided de-escalation of antiplatelet treatment in biomarker positive ACS patients undergoing PCI.

Randomised comparison of titanium-nitride-oxide coated stents with bare metal stents: five year follow-up of the TiNOX trial.

AIMS: Revascularisation with Titanium-Nitride-Oxide (TiNOX) coated stents is safe and effective in patients with de novo native coronary artery lesions. In the TiNOX trial there was a reduction in restenosis and major adverse cardiac events as compared with stainless steel stents of otherwise identical design. The purpose of the present study was to evaluate the long-term outcome of these patients over five years. METHODS AND RESULTS: In 2003, 92 patients with de novo lesions were randomly assigned to treatment with TiNOX coated stents (n=45) or stainless steel stents (n=47; control). Baseline characteristics were similar in both groups. Follow-up at six months and five years was obtained in 87 patients. Five patients were lost to follow-up due to emigration or change in home address. At six months and five years, significantly less major adverse cardiac events (MACE) occurred in the TiNOX group (7% vs. 27%, [p=0.02] respectively and 16% vs. 39%, [p=0.03]), largely driven by a reduced need for target-lesion revascularisation. No stent thrombosis occurred in the TiNOX group vs. one in the control group. Patients in the TiNOX-group had lower all-cause mortality and less myocardial infarction, but the difference was not statistically significant. CONCLUSIONS: Five-year follow-up after implantation of titanium-nitride-oxide coated stents is favourable with a low rate of MACE and no stent thrombosis compared to bare metal stents of identical design. The need for revascularisation at five years was 9% in the TiNOX and 25% in the control group with little progression of native coronary disease.

Fractional flow reserve predicts major adverse cardiac events after coronary stent implantation.

OBJECTIVES: Determination of fractional flow reserve (FFR) allows the functional assessment of coronary stenoses before and after an intervention. Preliminary data suggest that a FFR > or = 0.94 is associated with an excellent clinical outcome after stent implantation. However, these results were limited both by the number of patients included and the use of non-contemporary stent designs. We sought to determine the prognostic value of FFR measurements in a large patient cohort undergoing coronary stent implantation. METHODS: Eighty-nine consecutive patients were enrolled in whom a stent implantation was performed and a pressure wire was used as a guide wire. Patients were followed for at least 6 months. Death, myocardial infarction (MI) and target vessel revascularization (TVR) were considered cardiac events. A FFR > or = 0.94 was regarded as an optimal functional result. RESULTS: A complete follow-up was available in all patents. Pre-interventional FFR increased from 0.66 +/- 0.16 to 0.95 +/- 0.05 (p < 0.0001) after stent implantation. Sixteen (18%) events occurred during follow-up including 10 (11.2%) TVR. Final FFR was significantly higher in patients without compared to patients with an event (0.92 +/- 0.06 vs. 0.96 +/- 0.05, p < 0.003). By univariate analysis, the presence of diabetes mellitus, left ventricular function, residual diameter stenosis and final FFR were associated with a worse clinical outcome. In the multivariate analysis, only the final FFR and left ventricular function remained as significant predictors for cardiac events (relative risk, 3.50; 95% CI: 1.29-9.52, P < 0.014, and 0.97; 95% CI: 0.93-1.00, p = 0.047). CONCLUSION: These results demonstrate in a nonselected patient cohort a strong correlation between FFR values after coronary stenting and subsequent cardiac events. Further studies have to investigate whether outcome after stenting might be improved by guiding the procedure with a pressure guide wire.