Predictive factors of left ventricular ejection fraction improvement after myocardial infarction treated invasively.

Introduction: One indication for the implantation of a cardioverter-defibrillator is a reduction in the left ventricular ejection fraction (LVEF) ≤ 35%. However, in certain patients following an acute myocardial infarction (AMI) a gradual improvement in LVEF has been observed. The factors determining this increase in LVEF have not been conclusively determined. Aim: To ascertain the independent predictors associated with the improvement of LVEF in patients following AMI who underwent invasive treatment, while observing their progress over a 6-month follow-up period. Material and methods: Among 665 patients with AMI, a population with LVEF ≤ 35% was selected. After 6 months, a follow-up echocardiogram was performed. Further analysis compared patients with at least 5% improvement in LVEF (Group I) with those without an increase (Group II). Results: Group I consisted of 34 individuals out of 80 patients (43%) with LVEF ≤ 35%. The factors linked to a reduced probability of LVEF improvement were: higher levels of cardiac troponin T (cTnT) (OR 0.841 for 1 ng/ml increase in cTnT, CI 0.715-0.989; p = 0.037), presence of diabetes mellitus (OR = 0.217, 95% CI: 0.058-0.813, p = 0.023) and moderate or severe mitral regurgitation (OR = 0.178, 95% CI: 0.053-0.597; p = 0.005). Conclusions: The study findings indicate that the presence of severe or moderate mitral regurgitation is the most significant factor contributing to the lack of LVEF improvement following AMI. Moreover, the extent of myocardial damage, as indicated by elevated cTnT values, along with compromised adaptation to hypoxia in patients with diabetes, are identified as independent factors associated with reduced chances of an increase in LVEF.

Therapeutic hypothermia and postreperfusion myocardial injury in myocardial infarction.

Myocardial infarction is one of the main causes of death worldwide. Since the introduction of primary percutaneous coronary intervention (PPCI), the rate of patients who die of a myocardial infarction or suffer from numerous complications afterwards has significantly decreased. During PPCI, the patient sustains postreperfusion myocardial injury, which entails an extension of the myocardial infarct size related to ischemia. Research on the ways of limiting this phenomenon has been carried out for years. One of the investigated methods is hypothermia. The first animal studies have yielded promising results. The application of hypothermia has been proved to reduce the myocardial injury size provided that the cooling commenced before reperfusion. Moreover, the trial conducted by Götberg M. et al. showed a significant reduction of microvascular obstruction (MVO) in pigs subjected to hypothermia before reperfusion. MVO was assessed via ex vivo magnetic resonance imaging. The conducted randomized clinical trials have shown the possibility of applying mild hypothermia in conscious patients without causing significant complications. In the presented trials, hypothermia was induced and maintained using an intravascular catheter inserted into the inferior vena cava, cold saline solution infusions into peripheral veins or directly into the coronary arteries or via peritoneal hypothermia. The myocardial injury size was assessed via magnetic resonance imaging (MRI) or single photon emission computed tomography (SPECT). Despite the promising results obtained by Young-Sheng Wang et al., who applied selective intracoronary hypothermia and the myocardial infarct size (IS/MaR) was significantly reduced (p=0.022), it has not been unambiguously confirmed yet that hypothermia is effective as an adjunctive therapy for revascularization in myocardial injury size reduction during a myocardial infarction.

Risk stratification for complex ventricular arrhythmia complicating ST-segment elevation myocardial infarction.

OBJECTIVES: The primary aim of the study was to evaluate risk factors for ventricular fibrillation/sustained ventricular tachycardia (VF/VT) and to develop the risk score for prediction of VF/VT in patients with ST-segment elevation myocardial infarction (STEMI) treated invasively. The secondary aim was to assess the effect of VF/VT on mortality depending on timing of arrhythmia. PATIENTS AND METHODS: We analyzed 4363 consecutive patients with STEMI treated invasively. Among them, 163 patients with pre-reperfusion arrhythmia were excluded from the study. Group ventricular arrhythmias (VA) encompassed patients with VF/VT - those with reperfusion-induced arrhythmia were included into group VA1, whereas group VA2 consisted of patients with postreperfusion arrhythmia. The control group comprised patients free of VF/VT. RESULTS: VF or VT occurred in 313 (7.45%) patients - group VA1 encompassed 103 (32.9%) and group AV2 210 (67.1%) patients. Cardiogenic shock on admission [hazard ratio (HR) 3.5], new-onset atrial fibrillation (HR 2.1), incomplete revascularization (HR 1.7), prior myocardial infarction (HR 1.6) and symptom-to-balloon time more than 3 h (HR 1.3) were the independent predictors of VF/VT occurrence. In group VA2, the in-hospital and long-term mortality were 4- and 1.5-fold higher than in the arrhythmia-free population (20.5 vs. 4.5% and 36.2 vs. 22.6%, respectively; P<0.001). On the contrary, in group VA1, the long-term mortality was not significantly higher compared with the control group (26.2 vs. 22.6%; P=NS), whereas in-hospital mortality was almost three-fold increased (12.5 vs. 4.5%, respectively; P<0.001). CONCLUSION: The risk score based on simple clinical parameters might be useful for risk stratification for VF/VT in patients with STEMI. The predictive value of VF/VT was strongly dependent on timing of arrhythmia.

Prognostic Significance of Complex Ventricular Arrhythmias Complicating ST-Segment Elevation Myocardial Infarction.

The aim of the study was to assess the clinical significance of complex ventricular arrhythmias (VAs) (sustained ventricular tachycardia [sVT] and ventricular fibrillation [VF]) in patients with ST-segment elevation myocardial infarction (STEMI) depending on timing of arrhythmia. We analyzed 4,363 consecutive patients with STEMI treated invasively between 2004 and 2014. The median follow-up was 69.6 months (range: 0 to 139.8 months). The study population was divided into 2 main groups; VA group encompassed 476 patients (10.91%) with VAs, whereas 3,887 subjects (89.09%) without VT or VF were included into the control group. In VA population, prereperfusion VA (34.24%; n = 163) was the most common arrhythmia, whereas reperfusion-induced, early postreperfusion, and late postreperfusion VAs were diagnosed in 103 (21.64%), 103 (21.64%), and 107 (22.48%) patients, respectively. Every type of sVT or VF complicating STEMI portended significantly worse in-hospital prognosis, however a late onset arrhythmia was associated with the highest (over fivefold) and reperfusion-induced VA with the lowest (less than threefold) increase in mortality risk compared with the control group. On the contrary, long-term mortality was significantly increased only in subjects with late postreperfusion and prereperfusion VAs compared with VA-free population (43.93% and 36.81%, respectively vs 22.58%; p <0.001). Apart from cardiogenic shock on admission, late postreperfusion (hazard ratio 3.39) and prereperfusion VAs (hazard ratio 2.76) were the strongest independent predictors of death in the analyzed population. In conclusion, 1 in 10 patients with STEMI treated invasively was affected by sVT or VF. The clinical impact of VAs was strongly dependent on timing of arrhythmia.

Gender-related differences in long-term outcome among high-risk patients with myocardial infarction treated invasively.

INTRODUCTION: Treating acute myocardial infarction (AMI) with percutaneous coronary intervention (PCI) has an impact on improving long-term outcome. However, patients with other comorbidities are challenging, and are considered as a high-risk population. AIM: To assess gender-related differences in long-term prognosis after AMI among high-risk patients. MATERIAL AND METHODS: The single-center registry encompassed 4375 AMI patients treated with PCI. The following high-risk groups were selected: age > 70 group (n = 1081), glomerular filtration rate (GFR ) < 60 group (n = 848), diabetes mellitus (DM) group (n = 782), low ejection fraction (EF) group (n = 560) defined as EF < 35%, and incomplete coronary revascularization (ICR) group (n = 2008). Within each group, comparative analysis of long-term mortality with respect to gender and age was performed. RESULTS: There were no significant differences in long-term mortality with respect to gender among groups with age > 70 (29.0% vs. 30.3%) and GFR < 60 (37.2% vs. 42.3%) (both p = NS respectively for men vs. women). In the DM group (24.8% vs. 30.8%; p = 0.06) and EF < 35% group (36.3% vs. 44.5%; p = 0.07) there was a trend towards significance. The ICR group showed a higher mortality rate with respect to gender (19.7% vs. 27.3%; p < 0.001). Differences in survival assessed by the log-rank test were significant among ICR and EF < 35% groups. CONCLUSIONS: Female gender is related to higher long-term mortality among high-risk groups, but a statistically significant difference was observed only in patients with ICR and those with EF < 35%. Female gender may be associated with worse prognosis in diabetic patients, but it needs evaluation. However, worse prognosis in women was not independent and was associated mainly with other comorbidities and worse clinical characteristics.

Long-term prognosis is related to mid-term changes of glucometabolic status in patients with acute myocardial infarction treated invasively.

BACKGROUND: Glucometabolic status (GS) in patients with acute myocardial infarction (AMI) has an impact on prognosis, but it may change over time. AIM: To evaluate the prognosis after AMI treated invasively with respect to changes in GS assessed by oral glucose tolerance test at discharge and at mid-term follow-up visit (FU-visit). METHODS: Glucometabolic status was assessed by two-hour post-load glycaemia and defined as abnormal glucose tolerance (AGT) or normal glucose tolerance (NGT). Out of 454 in-hospital AMI survivors, 368 (81%) patients completed an FU-visit and were divided into four groups with respect to GS at discharge and FU-visit: group 1 - AGT at discharge and FU-visit (n = 101); group 2 - AGT at discharge and NGT at FU-visit (n = 48); group 3 - NGT at discharge and AGT at FU-visit (n = 114); and group 4 - NGT at discharge and FU-visit (n = 105). All-cause mortality was compared between groups with log-rank test. RESULTS: Median time from AMI to FU-visit was seven months. Median remote follow-up duration after AMI was 31 months. Two-hour post load glycaemia was significantly higher in patients with confirmed AGT at FU-visit than in other groups. Mortality was higher in group 1 (11.9%) than in group 2 (2.1%; p = 0.034) and group 4 (2.9%; p = 0.009). Mortality rates between group 2 and 4 were similar (2.1% vs. 2.9%; p = 0.781). There was no significant difference in mortality between group 1 and group 3 (11.9% vs. 6.1%; p = 0.114). Mortality in group 3 was over two-fold higher than in group 4; however, this difference was statistically non-significant (6.1% vs. 2.9%; p = 0.247). CONCLUSIONS: Prognosis for patients with confirmed AGT was unfavourable; however, patients with AGT at discharge, in whom GS improved, had similar mortality to subjects with persistent NGT. The major clinical implication from this study is the finding that reassessment of GS by repeated oral glucose tolerance test has significant prognostic value and makes initial risk stratification performed at discharge more reliable.

Platelet count and volume indices in patients with contrast-induced acute kidney injury and acute myocardial infarction treated invasively.

BACKGROUND: The aetiology of contrast-induced acute kidney injury (CI-AKI) is not well understood. We hypothesised that the pathophysiology of CI-AKI and impaired coronary reperfusion (IR), observed after invasive treatment of acute myocardial infarction (AMI), could be similar and might be related to platelet count (PC) and platelet volume indices (PVI). AIM: To evaluate the relation between PC, PVI, IR, and CI-AKI in patients with AMI treated invasively. METHODS: A single-centre study evaluated 607 consecutive AMI-patients treated invasively. Comparative analyses were performed between patients with CI-AKI and without CI-AKI for the total study population (CI-AKI, n = 156; 25.7% vs. nCI-AKI, n = 451; 74.3%), for patients with diabetes mellitus (CI-AKI-DM, n = 56; 9.2% vs. nCI-AKI-DM, n = 123; 20.3%), and for patients with baseline kidney dysfunction (CI-AKI-BKD, n = 31; 5.1% vs. nCI-AKI-BKD, n = 67; 11.0%). Subjects with IR, who developed CI-AKI, were compared to the remaining patients with respect to platelet parameters (CI-AKI-IR, n = 47; 7.7% vs. controls, n = 560; 92.3%). For total population, as well as studied subgroups, multivariate logistic regression analyses were performed to reveal independent factors associated with CI-AKI. The results of the models were reported as odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: PC was higher in CI-AKI-DM-patients (224.8 ± 62.8 × 10(9)/L vs. 197.9 ± 63.3 × 10(9)/L; p = 0.014) and in CI-AKI-BKD-patients (248.9 ± 86.5 × 10(9)/L vs. 202.5 ± 59.3 × 10(9)/L; p = 0.004) than in appropriate controls. Within the studied groups, there were no differences between CI-AKI and nCI-AKI patients with respect to PVI. Comparing CI-AKI-IR-patients with controls, no differences in PC or PVI were found. IR was observed more often in CI-AKI-patients than in nCI-AKI-patients only among diabetics (48.2% vs. 27.6%; p = 0.008). Increase in admission PC was independently associated with CI-AKI in patients with diabetes (per one unit increase OR 1.006; CI 1.0-1.01; p = 0.04) as well as with baseline kidney dysfunction (per one unit increase OR 1.01; CI 1,0-1,02; p = 0.02). CONCLUSIONS: Any similarities in the pathophysiology of CI-AKI and IR were not reflected in platelet parameters. CI-AKI development was not related to PVI; however, higher PC was an independent risk factor for CI-AKI in patients with diabetes or baseline kidney dysfunction.

Prognostic significance of HbA1c in patients with AMI treated invasively and newly detected glucose abnormalities.

BACKGROUND: Glucose abnormalities are frequent comorbidities influencing prognosis in patients with cardiovascular diseases. The objective of this study was to evaluate prognostic role of HbA1c in patients with acute myocardial infarction (AMI) treated invasively, who had newly detected glucose abnormalities. DESIGN: Single-centre registry encompassed 2146 survivors of AMI. In all patients without diabetes mellitus (DM), oral glucose tolerance test was performed before hospital discharge and interpreted according to the guidelines. METHODS: From the study population, two major groups with defined new glucose abnormalities and estimated HbA1c were selected: 457 patients with impaired glucose tolerance (IGT) and 306 patients with newly detected DM (newDM). In each of these groups, the median value of HbA1c was calculated and established as the cut-off point for further analysis. The median HbA1c for IGT group was 5.9% and for newDM was 7.0%. RESULTS: Patients with IGT and HbA1c ≤ 5.9% had significantly lower posthospital mortality (4.5%) than those with HbA1c >5.9% (25.0%; p<0.001). Similarly, patients with newDM and HbA1c ≤7.0% had lower mortality (6.4%) than those with HbA1c >7.0% (14.3%; p<0.05). Multivariate regression analysis revealed that increase of HbA1c was one of the strongest independent risk factors of death among IGT patients (HR 2.9, 95% CI 2.7-3.1; p < 0.001) and newDM (HR 1.53, 95% CI 1.39-1.66; p<0.05). CONCLUSIONS: Increase of HbA1c in patients with newly detected glucose abnormalities was associated with significantly reduced survival after AMI treated invasively. Moreover, increase of HbA1c in patients with IGT and newDM was one of the strongest independent risk factors of death in these populations.

Contrast-induced acute kidney injury in patients undergoing cardiac resynchronization therapy-incidence and prognostic importance. Sub-analysis of data from randomized TRUST CRT trial.

INTRODUCTION: Because data on contrast-induced acute kidney injury (CI-AKI) in patients undergoing cardiac resynchronization therapy (CRT-D) are scarce, we aimed to assess the incidence, natural course and prognostic importance of this syndrome in CRT recipients. METHODS: Study population consisted of 100 consecutive patients enrolled into the Triple Site Versus Standard Cardiac Resynchronization (TRUST CRT) trial, who were treated with CRT-D. Two patients were excluded up to 3 months after randomization and not analysed further. CI-AKI was defined as a rise in serum creatinine of at least 26.5 µmol/L (0.3 mg/dL) within 48 h after contrast exposure, or at least 50% increase from the baseline value during index hospital stay with CRT-D implantation according to KDIGO Clinical Practice Guideline for Acute Kidney Injury. RESULTS: Among 98 subjects of TRUST CRT trial, 10 patients (10.2%) developed CI-AKI after CRT-D implantation. In patients with glomerular filtration rate (GFR) <60 mL/min/1.73 m(2) on admission, the incidence of CI-AKI was almost twofold (15.4%) higher than in subjects with GFR ≥60 (8.3%). CRT-D recipients with CI-AKI had significantly higher mortality rate (50.0%) compared to those without CI-AKI (17.0%) during 30 months of follow-up (logrank p = 0.012). Multivariate Cox regression analysis showed CI-AKI as significant and independent risk factor for death in CRT-D recipients (hazard ratio 5.71; 95% CI 5.16-6.26; p = 0.001). CONCLUSIONS: Contrast-induced acute kidney injury is a serious and frequent procedural complication of CRT-D implantation with a significant negative influence on long-term survival. The results suggest that clinical evaluation regarding renal function should be considered in CRT-D recipients, both before and after device implantation.

Prognostic significance of hyperuricemia in patients with different types of renal dysfunction and acute myocardial infarction treated with percutaneous coronary intervention.

AIM: This study evaluated the impact of hyperuricemia (HUR) on outcome in patients with different types of impaired renal function (IRF) and acute myocardial infarction (AMI) treated invasively. METHODS: Out of 3,593 consecutive AMI patients treated invasively, 1,015 IRF patients were selected. The IRF group consisted of patients with baseline kidney dysfunction (BKD group) and/or patients with contrast-induced nephropathy (CIN group). HUR was defined as a serum uric acid concentration (SUAC) >420 µmol/l (>7 mg/dl). Independent predictors of death and major adverse cardiovascular events (MACE) were selected by the multivariate Cox-regression model. RESULTS: Remote mortality rates were higher in HUR patients: IRF (32.7 vs. 18.6%), BKD (41.3 vs. 25.9%), CIN (35.4 vs. 16.7%); all p < 0.001. HUR was an independent predictor of death in BKD (hazard ratio (HR) 1.38, p < 0.05). Each 100-µmol/l increase in SUAC was associated with a significant increase of HR for mortality: 1.087 in IRF patients, 1.108 in BKD patients, 1.128 in CIN patients; all p < 0.05. Remote major adverse cardiovascular event rates were higher in HUR patients: IRF (55.4 vs. 48.9%), CIN (56.8 vs. 48%); both p < 0.05. CONCLUSIONS: In AMI patients treated invasively, an increase in SUAC is an independent predictor of death within all types of renal dysfunction; HUR defined as SUAC >420 µmol/l (>7 mg/dl) is a predictor only in BKD patients.