Platelet function monitoring for stent thrombosis in critically III patients with an acute Coronary syndrome.

BACKGROUND: Patients after cardiac arrest or in cardiogenic shock due to acute coronary syndrome (ACS) are at high risk for stent thrombosis (ST) and recurrent cardiovascular events after primary percutaneous coronary intervention (PCI). High post-interventional platelet reactivity (HPR) might be an additional risk factor for ST in these critically ill patients. METHODS: Between 2006 and 2016, 401 critically ill patients from a cardiologic intensive care unit underwent platelet function testing after primary PCI using whole blood impedance aggregometry. After exclusion of patients with an abnormal platelet count, 357 patients have been included into the final analysis of this retrospective observational study. RESULTS: The incidence of definite early ST was 19.2% in patients with HPR to P2Y12 antagonists and 1.2% in patients without HPR. Likewise, the incidence of early ST in patients with HPR to acetylsalicylic acid (ASA) was 21.4% versus 1.8% in patients without HPR. In contrast, the incidence of late ST or recurrent myocardial infarction in untreated lesions was not associated with HPR to ASA or P2Y12 antagonists. CONCLUSIONS: Platelet function testing in critically ill ACS patients identified patients at high risk for early ST and might be beneficial for risk stratification.

Image quality and contrast agent exposure in cardiac computed tomography angiography prior to transcatheter aortic valve implantation procedures using different acquisition protocols.

BACKGROUND: ECG-gated cardiac computed tomography angiography (CCTA) has found widespread use for prosthesis sizing before transcatheter aortic valve implantation (TAVI). However, still little data exists on the optimal scan-strategy in such patients. We hypothesized that prospectively triggered CCTA can enable the visualization of aortic valve structures and peripheral arteries with lower radiation and contrast agent exposure in patients considered for TAVI compared to retrospectively gated protocols. METHODS: All studies were performed using a 256 multi-detector single source CT (iCT Philips, Best, Netherlands). With the prospective protocol the whole volume from the heart to the iliofemoral arteries scanned using prospective triggering. With the retrospective protocol a first retrospectively gated scan was performed for the heart and the iliofemoral part was subsequently scanned using a second non-triggered scan. Image quality was assessed semi-quantitatively and signal-to-noise- (SNR) and contrast-to-noise-ratios (CNR) were obtained for all scans. RESULTS: Prospective CCTA was performed in 74 and in 34 patients, respectively using non-tailored and BMI adapted scans, whereas retrospective CCTA was performed in 57 patients. Prospective scans required lower contrast agent administration compared to retrospective scans (71 ± 8 mL versus 91 ± 15 mL, p < 0.01) and resulted in lower radiation exposure (26 ± 7mSv for retrospective versus 15 ± 3mSv for non-tailored prospective versus 8 ± 4mSv for BMI-adapted prospective scans, p < 0.01). Visual image quality was better for the evaluation of aortic valve structures and similar for the assessment of iliofemoral anatomy with prospective versus retrospective scans. In addition, contrast density, SNR and CNR were higher in the ascending aorta with prospective versus retrospective CCTA (434 ± 98HU versus 349 ± 112HU; 35 ± 14 versus 24 ± 9 and 31 ± 11 versus 16 ± 7, p < 0.001 for all). Subsection analysis by heart rate groups demonstrated that both image quality and CNR were significantly higher in patients with prospective versus retrospective CCTA, irrespective of the heart rate during image acquisition. CONCLUSION: Prospectively triggered CCTA allows for improved visualization of aortic valve structures and peripheral arteries in patients scheduled for TAVI with simultaneously reduced contrast agent dose and radiation exposure. Therefore, this acquisition mode seems to be the preferred for the evaluation of patients considered for TAVI.

Efficacy of enteral ticagrelor in hypothermic patients after out-of-hospital cardiac arrest.

INTRODUCTION: Delivery of crushed ticagrelor via a nasogastric tube is a widely spread off-label use in unconscious patients following out-of-hospital cardiac arrest (OHCA). Notwithstanding the importance of a potent dual antiplatelet therapy in these patients, the efficacy of crushed ticagrelor after OHCA has not been established yet. METHODS: In a prospective, single-center, observational trial, 38 consecutive MI patients after OHCA were included. 27 patients (71.1 %) underwent mild induced hypothermia. The primary outcome was platelet inhibition at 24h measured by impedance aggregometry. RESULTS: There was sufficient platelet inhibition in most patients after OHCA. In all hypothermic patients, there was an adequate platelet inhibition by ticagrelor at 24 h (p < 0.001). 15 patients (39.5 %) had significant gastroesophageal reflux and one patient with significant reflux had inadequate platelet inhibition at 24 h. There were no stent thrombosis or recurrent atherothrombotic events in these patients. CONCLUSION: Administration of crushed ticagrelor via a nasogastric tube reliably inhibited platelet function in vitro and in vivo regardless of the presence of hypothermia in MI patients. Thus, platelet inhibition can be reliably achieved in MI patients during neuroprotective hypothermia following OHCA.

Usefulness of percutaneous aortic valve implantation to improve quality of life in patients >80 years of age.

Older patients with aortic stenosis cannot always be offered conventional surgical aortic valve replacement at an acceptable risk. Transcatheter aortic valve implantation (TAVI) is currently considered an alternative treatment option with lower periprocedural risks. However, its effect on post-TAVI quality of life and clinical improvement has not been systematically and prospectively evaluated in those of advanced age. Thus, the aim of the present study was to assess the clinical improvement in geriatric patients after TAVI, with a special emphasis on quality of life. In the present study, we assessed the quality of life and brain natriuretic peptide in patients aged >80 years, before and 6 months after transfemoral CoreValve implantation. Of 87 prospectively studied patients with severe, symptomatic aortic stenosis at an age of ≥81 years, 80 survived for 6 months and were able to attend the follow-up visit with a quality of life assessment, using the Medical Outcomes Trust Short Form 36-Item Health Survey (average age 86 ± 2.9 years). The average scores of all 8 health components had improved significantly after TAVI. The greatest gain was seen in physical functioning (improvement from 23.4 ± 6.0 to 67.8 ± 13.7; p <0.001). The lowest gain was seen in bodily pain (improved from 37.5 ± 9.4 to 51.3 ± 11.5; p <0.05). Similarly, both the physical and the mental component summary scores improved significantly. This was consistent with significant improvement in brain natriuretic peptide levels (5,770 ± 8,016 to 1,641 ± 3,650 ng/L; p <0.0001). In conclusion, the results of the present study have shown a significant clinical benefit from TAVI in a patient population aged ≥81 years.