Course Of Acute Ischemia Research Articles

ARTERIAL THROMBOSIS IN PATIENTS WITH TYPE 2 DIABETES AND COVID-19

The aim of the study: to assess the importance of the inflammatory status of the body in patients with diabetic 2 type and severe COVID-19 as an unfavorable factor for the occurrence of arterial thrombosis of the lower extremities, the course of acute ischemia and the prognosis for ischemic limb. Materials and Methods. The study included 35 patients with type 2 diabetes mellitus and acute arterial thrombosis of the lower extremities without a history of intermittent claudication with an ischemia of 6-12 h, who underwent urgent surgical successful thrombectomy. All studied patients were tested for the SARS-CoV-2 virus, 18 had a negative result (control group), the diagnosis of COVID-19 in 17 patients of the main group was confirmed by a transcriptional polymerase chain reaction. The average age of patients in the control group was 72.3 yrs, the main group — 69.8 yrs. Results. During examination, distal forms of arterial thrombosis were registered in 70.6 % of patients in the main group and 72.2 % in the controls. The concentration of myoglobin in the serum at 6 h after the surgery was the highest, reaching the highest values in patients of the main group. There was a significantly lower concentration of myoglobin in the control group during the first days after the restoration of blood flow. ICAM-1 levels were significantly higher in the COVID-19 group than in the control group during the first day after blood flow recovery. The association between endothelial dysfunction and subsequent thrombotic events is already well known in cardiovascular disease and diabetes. Six of our cases had comorbidities such as arterial hypertension, dyslipidemia, diabetes mellitus, and signs of chronic arterial disease. Thus, previous endothelial activation status caused by these comorbidities exacerbated endothelial dysfunction caused by SARS-CoV-2 infection and its inflammatory response, and may have been the cause of the most common fatalities described in these patients. Recurrences of thrombosis in the early postoperative period occurred in 5 (29.4 %) patients of the main group, which led to amputation. In the control group, recurrent thrombosis led to amputation in 2 (11.1 %) cases. In 7 patients of the main group (41.2 %) and 2 patients of the control group (11.1 %) in the early postoperative period developed adverse cardiopulmonary events, which in 4 patients of the main group (23.5 %) caused death. Conclusions. Оur results suggest the involvement of endothelial dysfunction and thrombosis in COVID-19. Consistent with this hypothesis, patients with type 2 diabetes mellitus and severe COVID-19 have been noted to have significant increase in serum level of inflammatory markers (TNF-α, IL-1β, IL-6, IL-8, IL-10). One of the significant factors of endothelial dysfunction as a result of our study was ICAM-1 thereby indicating the occurrence of macrophage activation syndrome. These thrombotic events can be fatal in patients with type 2 diabetes, and early diagnosis can help health professionals adjust the anticoagulation regimen and affect endothelial stabilization in high-risk patients, alleviate thrombogenic events, systemic inflammatory response syndrome, and multiorgan failure. K ey wor d s : type 2 diabetes mellitus, COVID-19, arterial thrombosis.

Ischämische Mitralklappeninsuffizienz

Ischemic mitral regurgitation (MR) is a complication of myocardial infarction due to coronary heart disease and may occur during the course of acute ischemia or delayed following adverse left ventricular remodeling. Acute ischemic MR represents a life-threatening condition and requires immediate surgical correction. Chronic ischemic MR develops time-delayed from acute ischemia and is caused by pathological remodeling of the left ventricle or valvular apparatus and mostly affects older patients with severe comorbidities. This common manifestation of ischemic MR contributes to the poor prognosis of such patients. Therapeutic options for the treatment of patients with chronic ischemic MR are limited as current guidelines are based on weak evidence and the optimal treatment is still a matter of controversy. Surgical correction of chronic ischemic MR is only advised in patients with indications for concomitant surgical revascularization and modern interventional or surgical treatment strategies to reduce MR are not included in these guidelines. Modern surgical options and new interventional procedures are available and will influence future treatment strategies of this chronic manifestation of MR.

Characterization of cardiac sarcoplasmic reticulum dysfunction during short-term, normothermic, global ischemia.

It has been proposed that breakdown of the excitation-contraction coupling system plays a pivotal role in myocardial dysfunction during the course of acute ischemia. We tested this hypothesis by characterizing the function of the sarcoplasmic reticulum at pH 7.1 and 6.4 after 7.5, 15, and 30 minutes of canine normothermic global ischemia. At pH 7.1, whole heart homogenate sarcoplasmic reticulum demonstrated a 49% depression of oxalate-supported calcium uptake at 7.5 minutes of ischemia, which progressed to 85% at 30 minutes of ischemia. At pH 6.4, control homogenate calcium uptake rates were significantly depressed, accompanied by a further depression in the ischemic groups. Isolated sarcoplasmic reticulum calcium uptake mirrored the effects of the whole heart homogenate. Calcium-stimulated magnesium-dependent ATPase (calcium-ATPase) activity was significantly depressed by both ischemia and acidosis, with a decrease in the coupling ratio (mumol calcium/mumol ATP) at 15 and 30 minutes of ischemia. Acidosis (pH 6.4) significantly shifted the sarcoplasmic reticulum pCalcium-ATPase curve to the right, increasing 50% activation from pCalcium 6.0 to 5.5 and depressing the maximum velocity (pH 7.1 = 2.06 +/- 0.14; pH 6.4 = 1.41 +/- 0.05 mumol Pi/mg per min; P less than 0.01). With ischemia, there was a progressive decrease in maximal activation of the calcium-ATPase enzyme and a progressive shift in calcium sensitivity to a higher concentration. Steady state calcium uptake, in the absence of oxalate, demonstrated a similar depression after 7.5 and 15 minutes of ischemia at pH 7.1 and 6.4, associated with a significant increase in the passive permeability coefficient for calcium.(ABSTRACT TRUNCATED AT 250 WORDS)