Combined effect of acute altitude exposure and vigorous exercise on platelet activation.

Exposure to high altitudes and exercise alters body's physiology and may cause acute cardiovascular events. Platelet activation is one of the key players in these events. Therefore, we investigated the effect of vigorous exercise at higher altitude (2650 m) on platelet aggregation and serum markers of platelet activation. 14 healthy subjects performed a step incremental ergometer test until exhaustion at the Environmental Research Station (UFS, 2650 m) at Zugspitze. Platelet aggregation and serum levels of endothelin-1, soluble p-selectin, platelet factor 4 and Chromogranin A were measured. Platelet activation was significantly enhanced after exercise at high altitude compared to measures immediately prior exercise. We detected significantly enhanced serum levels of endothelin-1 and soluble p-selectin whereas chromogranin A and platelet factor 4 remained unchanged. This effect might be due to increased endothelin-1 levels causing pulmonary vasoconstriction, rheological changes and direct platelet activation. This might be of clinical relevance, especially in patients with pre-existing diseases.

Postmortem interrogation of cardiac implantable electrical devices may clarify time and cause of death.

BACKGROUND: Postmortem interrogation of cardiac implantable electrical devices (CIED) in autopsy is not routinely performed. Thus, it remains unclear whether an interrogation might clarify time and cause of death. METHODS: Seventy of 4401 patients (1.6%) undergoing autopsy in 2014 and 2015 presented with a CIED. The explanted CIED were interrogated with respect to time and possible cause of death. Battery and lead parameters, clinical and technical alerts, and arrhythmia episodes were reviewed and afterwards correlated with the results of autopsy and clinical data. RESULTS: Twenty-five implantable cardioverter defibrillators (ICD) and 45 pacemaker (PM) devices were analyzed. Death was classified as cardiac by autopsy in 17 of 70 patients. Accordingly, presumably lethal ventricular arrhythmias were documented in six patients (8.6%; 5 ICD, 1 PM). In two of 30 patients with unknown cause of death after autopsy (6.7%), interrogation revealed ventricular tachycardia as potential reason for decease (1 ICD, 1 PM). Postmortem CIED interrogation additionally allowed to make a statement regarding the day of death in 36 patients (51%; 13 ICD, 23 PM). This was in accordance with clinical data or the results of autopsy in nine patients (25%; 3 ICD, 6 PM) or could even clarify the time of death in six patients (16.7%; 4 ICD, 2 PM). CONCLUSION: Interrogation of CIED revealed potentially lethal ventricular arrhythmias in 9 of 70 patients investigated and enabled valid estimation of the day of death in 15 patients. We therefore conclude that routinely performed postmortem CIED interrogation may clarify time and cause of death.

Alteration of Endothelin 1, MCP-1 and Chromogranin A in patients with atrial fibrillation undergoing pulmonary vein isolation.

BACKGROUND: The relation between arrhythmias and stress is known. The aim of our current study was to elucidate whether plasma levels of previously described stress parameters are altered in highly symptomatic patients with atrial fibrillation (AF) per se and in patients undergoing ablation therapy by pulmonary vein isolation (PVI). METHODS: 96 patients with AF undergoing PVI were recruited. Plasma levels of Endothelin-1 (ET-1), MCP-1 and Chromogranin-A (CGA) were measured before and three months after ablation completed with clinical follow-up with respect to AF recurrence. Additionally, we examined 40 healthy age- and sex-matched volunteers as a reference. RESULTS: Symptomatic AF patients showed increased levels of ET-1 compared to healthy controls (2.62pg/ml vs. 1.57pg/ml; p<0.01). Baseline levels of ET-1 were higher in patients presenting with AF after PVI (2.96pg/ml vs. 2.57pg/ml;p = 0.02). The temporal comparison revealed decreased ET-1 levels in patients without (2.57pg/ml vs. 2.33pg/ml; p<0.01) and unchanged ET-1 levels in patients with AF after PVI. Baseline MCP-1 was increased in AF patients vs. controls (268pg/ml vs. 227 pg/ml; p = 0.03). Both groups, with and without AF after PVI, showed an increase of MCP-1 compared to baseline (268pg/ml vs. 349pg/ml;p<0.01; 281pg/ml vs. 355pg/ml;p = 0.03). CGA was lower in AF patients compared to healthy controls (13.8ng/ml vs. 25.6ng/ml;p<0.01). Over time patients without AF after PVI showed an increase of CGA (14.2ng/ml vs. 20.7ng/ml;p<0.01). No change was observed in patients with AF after PVI. CONCLUSION: Our study demonstrated dysregulated levels of ET-1, MCP-1 and CGA in symptomatic AF patients. We could demonstrate an association between ET-1 to presence or absence of AF. Furthermore, we could show that a decrease of ET-1 as well as an increase of CGA after PVI, representing a trend towards control cohort levels, were both associated with restoration of sinus rhythm. These results provide new insights into the role of stress-related biomarkers in AF and AF treatment by ablation therapy.

Soluble Vascular Cell Adhesion Molecule-1 (VCAM-1) as a Biomarker in the Mouse Model of Experimental Autoimmune Myocarditis (EAM).

Vascular cell adhesion molecule-1 (VCAM-1) is strongly upregulated in hearts of mice with coxsackie virus-induced as well as in patients with viral infection-triggered dilated cardiomyopathy. Nevertheless, the role of its soluble form as a biomarker in inflammatory heart diseases remains unclear. Therefore, we investigated whether plasma levels of soluble VCAM-1 (sVCAM-1) directly correlated with disease activity and progression of cardiac dysfunction in the mouse model of experimental autoimmune myocarditis (EAM). EAM was induced by immunization of BALB/c mice with heart-specific myosin-alpha heavy chain peptide together with complete Freund`s adjuvant. ELISA revealed strong expression of cardiac VCAM-1 (cVCAM-1) throughout the course of EAM in immunized mice compared to control animals. Furthermore, sVCAM-1 was elevated in the plasma of immunized compared to control mice at acute and chronic stages of the disease. sVCAM-1 did not correlate with the degree of acute cardiac inflammation analyzed by histology or cardiac cytokine expression investigated by ELISA. Nevertheless, heart to body weight ratio correlated significantly with sVCAM-1 at chronic stages of EAM. Cardiac systolic dysfunction studied with positron emission tomography indicated a weak relationship with sVCAM-1 at the chronic stage of the disease. Our data provide evidence that plasma levels of sVCAM-1 are elevated throughout all stages of the disease but showed no strong correlation with the severity of EAM.

Influence of High Polyphenol Beverage on Stress-Induced Platelet Activation.

OBJECTIVES: Platelets are playing a crucial role in acute cardiovascular events. We investigated if physical stress activates platelets and whether this activation can be inhibited by a polyphenol-enriched diet. METHODS: Blood samples were taken from a total of 103 athletes three weeks before, one day before, immediately as well as 24 hours and 72 hours after a marathon run. Participants were randomized, double-blinded and divided into two groups. One group received a polyphenol-rich beverage the other the same beverage without polyphenols. Besides analysis of platelet counts and impedance-aggregometric-measurement of platelet activity, soluble P-selectin and Endothelin-A measurements were performed. RESULTS: In the control group, runners showed a 2.2-fold increased platelet aggregation directly after completing a marathon and within the following three days when compared with baseline values (p<0.01). In accordance, significant increases in sP-selectin (57.52ng/ml vs. 94.86ng/ml;p<0.01) were detectable. In contrast, for the group consuming a beverage with increased polyphenol content (upper quartile of study beverage intake) we did not find any increase of platelet aggregation. DISCUSSION: Physical stress causes a significant increase in platelet activity. Our results demonstrate that a diet enriched in polyphenols is capable of preventing platelet activation. These findings might indicate a diminished cardiovascular stress-reaction following pre-exposition to polyphenol-enriched diet.

Retrospective analysis of circulatory support with the Impella CP® device in patients with therapy refractory cardiogenic shock.

BACKGROUND: In cardiogenic shock (CS) the Impella CP® device provides a fast available left ventricular circulatory support of up to 4.0L/min. However, the use of the Impella CP® device was not systematically analysed yet. METHODS: We performed a retrospective analysis of 28 consecutive patients suffering from severe therapy refractory CS treated with Impella CP®. Mortality was estimated using the SAPS II-Score. Primary outcome was 30-day survival. We compared the different aetiologies of CS and the effect of additional extracorporeal life support (ECLS). RESULTS: Aetiology of CS was acute coronary syndrome (ACS) in 15 patients, 9 patients received additional therapy with ECLS. SAPS II was 73±14, representing an estimated mortality of 87.1%. 18 patients deceased representing a 30-day survival of 36%. Comparing the different aetiologies, ACS-CS patients show a trend towards better survival. Additional therapy with ECLS did not change 30-day survival. In 3 cases, vascular complication needing surgical treatment occurred. All other patients showed no relevant complications except for the commonly seen haemolysis with consecutive need of transfusion. CONCLUSION: Our data could demonstrate that the Impella CP® application in these severely diseased patients is feasible and safe. Compared to the estimated mortality, the 30-day survival seems to be improved.