Acute coronary syndromes: Blood transfusion in patients with acute MI and anaemia

Clinical Characteristics and Long-Term Outcomes of Patients With Differing Haemoglobin Levels Undergoing Semi-Urgent and Elective Percutaneous Coronary Intervention in an Asian Population

Introduction

This study aimed to investigate the impact of anaemia on long-term clinical outcomes in patients who underwent semi-urgent and elective percutaneous coronary intervention (PCI) in an Asian population. Although the effects of anaemia on outcomes in Asian patients are well studied for acute coronary syndrome, its impact on Asian patients undergoing semi-urgent and elective PCI is unclear.

Methods

This was a retrospective cohort study of patients who underwent semi-urgent and elective PCI from January 1, 2014, to December 31, 2015, at a tertiary academic centre. A total of 1,685 patients were included. They were stratified into three groups: normal (≥12 g/dL), intermediate (10–11.9 g/dL), and low (<10 g/dL) haemoglobin levels. Demographics, risk factors, and end-points including the 5-point major adverse cardiac and cerebrovascular events (MACCE) (all-cause death, subsequent stroke, myocardial infarction, congestive cardiac failure, and target lesion revascularisation), cardiovascular death, and bleeding events were analysed.

Results

Patients in intermediate and low haemoglobin level groups were older with more comorbidities. Compared to the normal haemoglobin level group, low haemoglobin level group patients were associated with an increased risk of composite endpoints of all-cause death, subsequent stroke, myocardial infarction, congestive cardiac failure, and target lesion revascularisation [adjusted hazard ratio (aHR) 1.89, 95% confidence interval (CI):1.22, 2.92; p = 0.004]. This was driven by the increased risk of target lesions revascularisation observed in the low haemoglobin level group compared to the normal haemoglobin level group (aHR 17.74, 95% CI: 1.74, 180.80; p = 0.015). The patients in the low haemoglobin level group were also associated with a higher risk of bleeding events compared to the normal haemoglobin level group (aHR 7.18, 95% CI: 1.13, 45.40; p = 0.036).

Conclusion

In our Asian cohort, patients with anaemia undergoing PCI were associated with a higher comorbid burden. Despite adjustments for comorbidities, these patients had higher mortality and worse cardiovascular outcomes following contemporary PCI.

Red blood cell transfusion in patients with ST-elevation myocardial infarction-a meta-analysis of more than 21,000 patients

BACKGROUND

Red blood cell transfusion remains controversial in patients with acute coronary syndromes and particularly in patients with ST-elevation myocardial infarction (STEMI).

METHODS

We systematically searched PubMed, Cochrane, EMBASE, and Web of Science for studies published until January 2017 describing the outcomes in patients with STEMI who received red blood cell transfusion, compared with patients who did not.

RESULTS

A total of 21,770 patients with STEMI from 5 cohort studies were included in the meta-analysis, 984 (4.5%) received red blood cell transfusion and 20,786 (95.4%) did not. Red blood cell transfusion was associated with a higher risk of in-hospital and long-term mortality, emergency repeated percutaneous coronary intervention (PCI), reinfarction rate, stroke rate, and heart failure. The group with red blood cell transfusion had a slightly higher incidence of diabetes mellitus and hypertension, but a lower incidence of smoking. The two groups had the same incidence of prior myocardial infarction, prior coronary artery bypass graft surgery and malignancy. Prior heart failure, prior stroke and prior PCI were more frequent in the group that had received red blood cell transfusion. The mean nadir haemoglobin was 8.5 ± 0.1 g/dl in the group with red blood cell transfusion and 12.5 ± 0.4 g/dl in the control group, p < 0.001.

CONCLUSIONS

Red blood cell transfusion increases the morbidity and mortality in patients with STEMI. This difference could not be explained by the higher morbidity in the red blood cell transfusion group alone. Further randomised controlled trials are required to provide a reliable haemoglobin threshold for these patients.

Relation of Use of Red Blood Cell Transfusion After Acute Coronary Syndrome to Long-Term Mortality

Registry studies have associated red blood cell (RBC) transfusion with increased in-hospital mortality in patients with acute coronary syndrome (ACS). The impact on long-term mortality after 1-year follow-up remains unknown. Consecutive patients with ACS (n = 2,009) of a prospective Genetic Predisposition of Coronary Artery Disease cohort were followed for a median of 8.6 years (95% confidence interval [CI] 8.59 to 8.69). After discharge, 1,937 (96%) patients survived for over 30 days. Of those survivors, a subgroup of previously transfusion-naïve patients 85/1,937 (4.4%) who had received at least 1 RBC transfusion during hospitalization were compared with 1,278/1,937 patients (66.0%) who had not received any transfusion either during the hospitalization or the entire follow-up. Unadjusted long-term mortality was significantly higher in the patients transfused with RBC compared with their counterparts not transfused with RBC (58.8% vs 20.3%, p <0.001). The results remained significant for hazard ratio (HR) 1.91, 95% CI 1.39 to 2.63, p <0.001, after multivariate Cox proportional hazards model analysis and were similar after 1-year landmark analysis (HR 1.90, 95% CI 1.34 to 2.70, p <0.001). The higher all-cause mortality was largely explained by cancer mortality (15.3% vs 4.1%, p <0.001) and cardiovascular mortality (34.1% vs 12.1%, p <0.001). After 1:1 propensity score matching (n = 65 vs 65), the association of RBC transfusion with worse survival remained significant (HR 2.70, 95% CI 1.48 to 4.95, p = 0.001). Inverse probability weighted Cox analyses turned out similar results (HR 2.07, 95% CI 1.38 to 3.11, p <0.001). In conclusion, the strong association of need for RBC transfusion with increased mortality continued for patients with ACS even after a 1-year follow-up.

Gender differences in coronary angiography, subsequent interventions, and outcomes among patients with acute coronary syndromes

BACKGROUND

The objective was to investigate whether gender disparities are found in referrals of patients with acute coronary syndromes to percutaneous coronary interventions (PCIs) or coronary artery bypass grafting (CABG) and, furthermore, to study gender differences in complications and mortality.

METHODS

All consecutive coronary angiographies (CAs) and PCIs performed in Sweden and Iceland are prospectively registered in the Swedish Coronary Angiography and Angioplasty Registry. For the present analysis, data of patients with acute coronary syndromes, enrolled in 2007-2011, were used to analyze gender differences in revascularization, in-hospital complications, and 30-day mortality.

RESULTS

A total of 106,881 CAs were performed during the study period. In patients with significant coronary artery disease, the adjusted odds ratio (OR) for women to undergo PCI compared with men was 0.95 (95% CI 0.92-0.99) and 0.81 (0.76-0.87) for referrals to CABG. In patients with 1-vessel disease, women were less likely to undergo PCI than men, but women with 2- or 3-vessel or left main stem disease were more likely to undergo PCI. All in-hospital complications after CA followed by PCI were more frequent among women (adjusted OR 1.58 [1.47-1.70]). There was no gender difference in adjusted 30-day mortality after PCI (1.02 [0.92-1.12]) and after CABG (0.97 [0.72-1.31]).

CONCLUSIONS

After CA showing 1-vessel disease, women as compared with men were less likely to undergo PCI. In the group with 2- or 3-vessel disease or left main stem stenosis, women were more likely to undergo PCI but less likely to undergo CABG. However, there was no gender difference in 30-day mortality.

Effect of cardiogenic shock hospital volume on mortality in patients with cardiogenic shock

Background

Cardiogenic shock (CS) is associated with significant morbidity, and mortality rates approach 40% to 60%. Treatment for CS requires an aggressive, sophisticated, complex, goal‐oriented, therapeutic regimen focused on early revascularization and adjunctive supportive therapies, suggesting that hospitals with greater CS volume may provide better care. The association between CS hospital volume and inpatient mortality for CS is unclear.

Methods and Results

We used the Nationwide Inpatient Sample to examine 533 179 weighted patient discharges from 2675 hospitals with CS from 2004 to 2011 and divided them into quartiles of mean annual hospital CS case volume. The primary outcome was in‐hospital mortality. Multivariate adjustments were performed to account for severity of illness, relevant comorbidities, hospital characteristics, and differences in treatment. Compared with the highest volume quartile, the adjusted odds ratio for inpatient mortality for persons admitted to hospitals in the lowest‐volume quartile (≤27 weighted cases per year) was 1.27 (95% CI 1.15 to 1.40), whereas for admission to hospitals in the low‐volume and medium‐volume quartiles, the odds ratios were 1.20 (95% CI 1.08 to 1.32) and 1.12 (95% CI 1.01 to 1.24), respectively. Similarly, improved survival was observed across quartiles, with an adjusted inpatient mortality incidence of 41.97% (95% CI 40.87 to 43.08) for hospitals with the lowest volume of CS cases and a drop to 37.01% (95% CI 35.11 to 38.96) for hospitals with the highest volume of CS cases. Analysis of treatments offered between hospital quartiles revealed that the centers with volumes in the highest quartile demonstrated significantly higher numbers of patients undergoing coronary artery bypass grafting, percutaneous coronary intervention, or intra‐aortic balloon pump counterpulsation. A similar relationship was demonstrated with the use of mechanical circulatory support (ventricular assist devices and extracorporeal membrane oxygenation), for which there was significantly higher use in the higher volume quartiles.

Conclusions

We demonstrated an association between lower CS case volume and higher mortality. There is more frequent use of both standard supportive and revascularization techniques at the higher volume centers. Future directions may include examining whether early stabilization and transfer improve outcomes of patients with CS who are admitted to lower volume centers.

Update: acute coronary syndromes (VI): treatment of acute coronary syndromes in the elderly and in patients with comorbidities

Acute coronary syndromes have a wide spectrum of clinical presentations and risk of adverse outcomes. A distinction should be made between treatable (extent of ischemia, severity of coronary disease and acute hemodynamic deterioration) and untreatable risk (advanced age, prior myocardial damage, chronic kidney dysfunction, other comorbidities). Most of the patients with "untreatable" risk have been excluded from the "guideline-generating" clinical trials. In recent years, despite the paucity of specific randomized trials, major advances have been completed in the management of elderly patients and patients with comorbidities: from therapeutic nihilism to careful titration of antithrombotic agents, a shift toward the radial approach to percutaneous coronary interventions, and also to less-invasive cardiac surgery. Further advances should be expected from the development of drug regimens suitable for use in the elderly and in patients with renal dysfunction, from a systematic multidisciplinary approach to the management of patents with diabetes mellitus and anemia, and from the courage to undertake randomized trials involving these high-risk populations.

Arginase regulates red blood cell nitric oxide synthase and export of cardioprotective nitric oxide bioactivity

The theory that red blood cells (RBCs) generate and release nitric oxide (NO)-like bioactivity has gained considerable interest. However, it remains unclear whether it can be produced by endothelial NO synthase (eNOS), which is present in RBCs, and whether NO can escape scavenging by hemoglobin. The aim of this study was to test the hypothesis that arginase reciprocally controls NO formation in RBCs by competition with eNOS for their common substrate arginine and that RBC-derived NO is functionally active following arginase blockade. We show that rodent and human RBCs contain functional arginase 1 and that pharmacological inhibition of arginase increases export of eNOS-derived nitrogen oxides from RBCs under basal conditions. The functional importance was tested in an ex vivo model of myocardial ischemia-reperfusion injury. Inhibitors of arginase significantly improved postischemic functional recovery in rat hearts if administered in whole blood or with RBCs in plasma. By contrast, arginase inhibition did not improve postischemic recovery when administered with buffer solution or plasma alone. The protective effect of arginase inhibition was lost in the presence of a NOS inhibitor. Moreover, hearts from eNOS(-/-) mice were protected when the arginase inhibitor was given with blood from wild-type donors. In contrast, when hearts from wild-type mice were given blood from eNOS(-/-) mice, the arginase inhibitor failed to protect against ischemia-reperfusion. These results strongly support the notion that RBCs contain functional eNOS and release NO-like bioactivity. This process is under tight control by arginase 1 and is of functional importance during ischemia-reperfusion.