Previous angina alters in-hospital outcome in TIMI 4. A clinical correlate to preconditioning?

Potential Effects of Ischemic Postconditioning and Changes in Heat Shock Protein 72 in Patients with Acute Myocardial Infarction without Prodromal Angina

The effectiveness of ischemic postconditioning (iPoC) in patients with ST-elevation myocardial infarction (STEMI) without ischemic preconditioning has not been determined. Therefore, we investigated the impact of iPoC and its potential mechanism related to heat shock protein 72 (HSP72) induction on myocardial salvage in patients with STEMI without prodromal angina (PA).We retrospectively analyzed data from 102 patients with STEMI with successful reperfusion among 323 consecutive patients with acute coronary syndrome. Among these, 55 patients with iPoC (iPoC (+) ) underwent 4 cycles of 60-second inflation and 30-second deflation of the angioplasty balloon. Both the iPoC (+) and iPoC (-) groups were divided into 2 further subgroups: patients with PA (PA (+) ) and those without (PA (-) ). We analyzed HSP72 levels in neutrophils, which were measured until 48 hours after reperfusion. I-123 β-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) scintigraphy was performed within a week of reperfusion therapy. In 64% of patients, thallium-201 (TL) scintigraphy was performed 6-8 months after STEMI onset.Using BMIPP and TL, in the PA (-) subgroups, the iPoC (+) group had a significantly greater myocardial salvage ratio than the iPoC (-) group. iPoC was identified as an independent predictor of the myocardial salvage ratio. The HSP72 increase ratio was significantly elevated in the iPoC (+) PA (-) group. Importantly, the myocardial salvage effect in patients without PA was significantly correlated with the HSP72 increase ratio, which was greater in patients with iPoC.These results suggest the potential impact of iPoC via HSP72 induction on myocardial salvage; however, the effects may be limited to patients with STEMI without PA.

Ticagrelor enhances the cardioprotective effects of ischemic preconditioning in stable patients undergoing percutaneous coronary intervention: the TAPER-S randomized study

BACKGROUND

Ticagrelor improves clinical outcomes in patients with acute coronary syndromes compared with clopidogrel. Ticagrelor also inhibits cell uptake of adenosine and has been associated with cardioprotective effects in animal models. We sought to investigate the potential cardioprotective effects of ticagrelor, as compared with clopidogrel, in stable patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

This was a Prospective Randomized Open Blinded End-points (PROBE) trial enrolling stable patients with coronary artery disease (CAD) requiring fractional flow reserve-guided PCI of intermediate epicardial coronary lesions. ST-segment elevation at intracoronary electrocardiogram (IC-ECG) during a two-step sequential coronary balloon inflations in the reference vessel during PCI was used as an indirect marker of cardioprotection induced by ischemic preconditioning (IPC). The primary endpoint of the study was the comparison of the delta (Δ) (difference) ST-segment elevation measured by IC-ECG during two-step sequential coronary balloon inflations.

RESULTS

Fifty-three patients were randomized to either clopidogrel or ticagrelor. The study was stopped earlier because the primary endpoint was met at a pre-specified interim analysis. ΔST-segment elevation was significantly higher in ticagrelor as compared to clopidogrel arms (P < 0.0001). Ticagrelor was associated with lower angina score during coronary balloon inflations. There was no difference in coronary microvascular resistance between groups. Adenosine serum concentrations were increased in patients treated with ticagrelor as compared to those treated with clopidogrel.

CONCLUSIONS

Ticagrelor enhances the cardioprotective effects of IPC compared with clopidogrel in stable patients with CAD undergoing PCI. Further studies are warranted to fully elucidate the mechanisms through which ticagrelor may exert cardioprotective effects in humans.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique Identifier: NCT02701140.

Mesenchymal stromal cells for improvement of cardiac function following acute myocardial infarction: a matter of timing

Acute myocardial infarction (AMI) is the leading cause of cardiovascular death and remains the most common cause of heart failure. Reopening of the occluded artery, i.e., reperfusion, is the only way to save the myocardium. However, the expected benefits of reducing infarct size are disappointing due to the reperfusion paradox, which also induces specific cell death. These ischemia-reperfusion (I/R) lesions can account for up to 50% of final infarct size, a major determinant for both mortality and the risk of heart failure (morbidity). In this review, we provide a detailed description of the cell death and inflammation mechanisms as features of I/R injury and cardioprotective strategies such as ischemic postconditioning as well as their underlying mechanisms. Due to their biological properties, the use of mesenchymal stromal/stem cells (MSCs) has been considered a potential therapeutic approach in AMI. Despite promising results and evidence of safety in preclinical studies using MSCs, the effects reported in clinical trials are not conclusive and even inconsistent. These discrepancies were attributed to many parameters such as donor age, in vitro culture, and storage time as well as injection time window after AMI, which alter MSC therapeutic properties. In the context of AMI, future directions will be to generate MSCs with enhanced properties to limit cell death in myocardial tissue and thereby reduce infarct size and improve the healing phase to increase postinfarct myocardial performance.

Observation of the effectiveness of clinical indicators of cardiac shock wave therapy in patients with ischemic heart disease: A systematic review and meta-analysis

Objective

Ischemic heart disease (IHD) has a high prevalence and mortality rate, imposing a heavy burden on patients and society, and there is still a need to optimize treatment options for IHD patients. Cardiac shock wave therapy (CSWT) is gaining popularity as a new treatment for IHD patients. The objective of this meta-analysis is to reassess the effects of CSWT on IHD patients in light of the limited number of clinical studies included in previously published reviews, inconsistent methodological quality, and unclear outcomes.

Methods

From database creation until September 1, 2022, 4 English databases and 3 Chinese databases were rigorously searched for any current controlled trials of CSWT for IHD. The Cochrane Risk of Bias Assessment Tool was used for methodological quality assessment. Review Manager v.5.4 software was used for meta-analysis.

Results

Nineteen published controlled trials totaling 1,254 subjects were included. Results showed that CSWT could enhance left ventricular function and myocardial viability, improve cardiac function and alleviate angina pectoris symptoms. The effects of CSWT and control groups on SAQ scores and exercise time were not statistically significant.

Conclusion

According to this systematic review and meta-analysis, CSWT may be beneficial for a number of IHD clinical indications. To verify these findings, more RCT studies with bigger sample numbers and higher methodological standards are required in the future.

Cardiac Shock Wave Therapy in Coronary Artery Disease: A Systematic Review and Meta-Analysis

Objective

Coronary artery disease (CAD) has been one of the leading causes of morbidity and mortality worldwide. Cardiac shock wave therapy (CSWT) is a novel and non-invasive therapy for CAD. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy of CSWT on CAD.

Methods and results

We performed a comprehensive search of electronic databases such as PubMed, Embase, the Cochrane Library, and Wanfang Data in October 2021. The results were reported as weighted mean difference (WMD) with a 95% confidence interval (CI). Statistical heterogeneity scores were assessed with the standard Cochran's Q test and the I 2 statistic. A total of 8 randomized trials and 2 prospective cohort studies, together involving 643 patients (n = 336 CSWT and n = 307 control), were included in our study. Eight studies with 371 patients showed significantly improved rest left ventricular ejection fraction (LVEF) with CSWT as compared to that of the control group (WMD 3.88, 95% CI 1.53-6.23, p = 0.001, I 2 = 51.2%). Seven studies with 312 patients reported left ventricular internal diameter in diastole (LVIDd) were markedly decreased in the CSWT group compared to the control group (WMD -1.81, 95% CI -3.23 to -0.39, p = 0.012, I 2 = 20.3%). The summed stress score significantly favored the CSWT group (WMD -3.76, 95% CI -6.15 to -1.37, p = 0.002, I 2 = 56.8%), but there was no significant difference for the summed rest score. Our data were acquired from studies without a perceived high risk of bias, so plausible bias is unlikely to seriously affect the main findings of the current study.

Conclusion

Based on data from our present meta-analysis, CSWT was shown to moderately improve myocardial perfusion and cardiac function among patients with CAD, which would provide the clinicians with a meaningful and valuable option.

Systematic Review Registration

The meta-analysis was registered on the Open Science Framework (OSF) (https://osf.io/r2xf9).

Influence of Hyperglycemia During Different Phases of Ischemic Preconditioning on Cardioprotection-A Focus on Apoptosis and Aggregation of Granulocytes

BACKGROUND

Ischemic preconditioning (IPC) protects the myocardium against ischemia/reperfusion injury. Evidence suggests that hyperglycemia inhibits IPC-induced cardioprotection. The effects of hyperglycemia initiated during different phases of IPC on myocardial injury were characterized with emphasis on apoptosis and aggregation of polymorphonuclear granulocytes (PMN).

METHODS

Male Wistar rats were subjected to 35 min of myocardial ischemia and 2 h of reperfusion. Control animals were not further treated. IPC was induced by three cycles of 3 min ischemia and 5 min of reperfusion before major ischemia. Hyperglycemia (blood glucose more than 22.2 mmol/L) was induced by glucose administration with or without IPC during different phases (trigger- (before ischemia), mediator- (during ischemia), early reperfusion-phase). One additional group received an anti-PMN-antibody before ischemia. Infarct size was quantified by triphenyltetrazolium chloride staining. Cytochrome C release and B-cell lymphoma two (Bcl-2) expression were assessed by western blot analysis. Poly-ADP-Ribose staining and PMN accumulation were quantified with immunohistochemistry and histochemistry.

RESULTS

IPC reduced infarct size compared with control. Hyperglycemia completely abolished IPC-induced cardioprotection independent of the time point of initiation. Hyperglycemia before and during major ischemia but without IPC also slightly reduced infarct size. IPC reduced the accumulation of PMNs. This effect was reversed by hyperglycemia during trigger- and mediator-phase but not by hyperglycemia during reperfusion. Hyperglycemia alone had no effect on PMN accumulation. In all treatment groups, signs of myocardial apoptosis were reduced compared with control. IPC alone, combined with hyperglycemia and anti-PMN treatment, reduced apoptosis by a Bcl-2-associated mechanism. Hyperglycemia alone reduced apoptosis by a Bcl-2-independent pathway.

CONCLUSION

Hyperglycemia inhibits IPC-induced cardioprotection independent of its onset. Furthermore, hyperglycemia prevents apoptosis and IPC-induced reduction of PMN aggregation.

Heart failure after myocardial infarction: incidence and predictors

Aims

The aim of the present paper was to provide an up‐to‐date view on epidemiology and risk factors of heart failure (HF) development after myocardial infarction.

Methods and results

Based on literature review, several clinical risk factors and biochemical, genetic, and imaging biomarkers were identified to predict the risk of HF development after myocardial infarction.

Conclusions

Heart failure is still a frequent complication of myocardial infarction. Timely identification of subjects at risk for HF development using a multimodality approach, and early initiation of guideline‐directed HF therapy in these patients, can decrease the HF burden.

Co-morbidities and co-medications as confounders of cardioprotection-Does it matter in the clinical setting?

The translation of cardioprotection from robust experimental evidence to beneficial clinical outcome for patients suffering acute myocardial infarction or undergoing cardiovascular surgery has been largely disappointing. The present review attempts to critically analyse the evidence for confounders of cardioprotection in patients with acute myocardial infarction and in patients undergoing cardiovascular surgery. One reason that has been proposed to be responsible for such lack of translation is the confounding of cardioprotection by co-morbidities and co-medications. Whereas there is solid experimental evidence for such confounding of cardioprotection by single co-morbidities and co-medications, the clinical evidence from retrospective analyses of the limited number of clinical data is less robust. The best evidence for interference of co-medications is that for platelet inhibitors to recruit cardioprotection per se and thus limit the potential for further protection from myocardial infarction and for propofol anaesthesia to negate the protection from remote ischaemic conditioning in cardiovascular surgery. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.23/issuetoc.

Pre-infarction angina is associated with improved prognosis in diabetic patients with ST-elevation myocardial infarction - data from a contemporary cohort

BACKGROUND

Pre-infarction angina (PIA) is associated with improved prognosis in patients with ST-elevation myocardial infarction (STEMI). Some studies suggest that diabetes may blunt the effect of ischaemic preconditioning. We sought to study the impact of PIA in diabetic patients with STEMI.

METHODS

Consecutive patients with STEMI who underwent primary angioplasty were included. PIA was defined as ≥1 episode of chest pain during the week preceding STEMI diagnosis. Incident major adverse cardiovascular events (MACE) were defined as the first occurrence of all-cause death, stroke or acute myocardial infarction.

RESULTS

Of the 1143 included patients, 25% were diabetic and 32% had a history of PIA. Diabetic patients with PIA had smaller infarct sizes as estimated by peak creatine kinase (CK) [1144 (500-2212) vs. 1715 (908-3309) U/L, P = 0.003] and peak troponin [3.30 (1.90-6.58) vs. 4.88 (2.50-9.58) ng/ml, P = 0.002], compared to diabetics without PIA. They also had a lower likelihood of evolving with moderate to severe reduced left ventricle ejection fraction (LVEF) (25.6%, n = 22 vs. 46.6%, n = 82, P = 0.001). In non-diabetic patients, PIA was associated with reduced peak CK [1549 (909-2909) vs. 1793 (996-3078), P = 0.0497], but not troponin (3.74 [2.23-7.11] vs. 4.56 [2.44-7.77] ng/ml, P = 0.19), and was not associated with reduced LVEF (32.0%, n = 85 vs. 37.4%, n = 207, P = 0.13). Both diabetic and non-diabetic patients with PIA had a lower likelihood of evolving with a Killip class III/VI (non-diabetic patients: 5.6% vs. 14.1%, P = 0.002; diabetic patients: 12.8% vs. 24.6%, P = 0.049). Over a median follow-up of 18.0 (12.1-25.5) months, PIA was associated with a significant reduction in the incidence of MACE [hazard ratio 0.52, 95% confidence interval (CI) 0.37-0.74, P < 0.001], irrespective of diabetes status.

CONCLUSION

PIA is an independent predictor of favourable outcomes in the setting of STEMI for both diabetic and non-diabetic patients.

Effect of ischemic postconditioning during primary percutaneous coronary intervention for patients with ST-segment elevation myocardial infarction: A single-center cross-sectional study

Background and Objective

Reperfusion therapy for acute myocardial infarction has been shown to reduce mortality, yet it may also have deleterious effects, including myocardial necrosis and no-reflow. Postconditioning is known measure for cardioprotection from reperfusion injury in animal model. Postconditioning is known measure for cardioprotection from reperfusion injury in animal model and human studies have shown inconsistent results.

Materials and Methods

From February 2013 through October 2014, at Institute of Postgraduate Medical Education and Research, Kolkata Cardiology department, we randomized 43 patients with acute ST-segment elevation myocardial infarction (STEMI) who were undergoing conventional primary percutaneous coronary intervention (PCI) (22 patients) and PCI with postconditioning by repeated transient balloon occlusion after establishment of flow (21 patients). Total creatine kinase-muscle/brain (CPK-MB) released within 72 h was compared as a surrogate marker of infarct size. Myocardial blush grade between two groups was also compared.

Results

The area under curve of serum creatine kinase (CK) release during the 1^st 72 h of reperfusion was significantly reduced (P = 0.0347) in the postconditioned group compared with the control group, averaging 9632 IU in postconditioned compared with 13493 IU in control group which represented 29% of reduction of infarct size. The peak of CPK-MB release was markedly lower in the postconditioned (290 ± 16.24 IU/L) than in the control (414.2 ± 51.34 IU/L) group (P ≤ 0.0001). Blush grading was also significantly improved in postconditioned group (P = 0.005). Mean ST-segment deviation at 48 h between cases and control groups was 0.87 ± 0.68 and 1.4 ± 0.94, respectively (P = 0.08).

Conclusion

In patients with STEMI, postconditioning significantly improves blush grading and enzymatic infarct size reduction with a trend toward significant reduction of mean ST-segment deviation.

Impact of Previous Angina on Clinical Outcomes in ST-Elevation Myocardial Infarction Underwent Percutaneous Coronary Intervention

The present study sought to assess the impact of previous angina symptoms on real world clinical outcomes in patients with ST-elevation myocardial infarction (STEMI) who had undergone successful percutaneous coronary interventions using drug-eluting stents (DES). Patients were selected from 13,650 consecutive patients enrolled in the Korea Acute Myocardial Infarction-National Institute of Health (KAMIR-NIH) registry. A total of 5167 STEMI patients were divided into a previous-angina group (n=1129) and a control group (n=4038). Major adverse cardiac and cerebrovascular events (MACCEs) that included all-cause death, recurrent myocardial infarction (re-MI), repeat PCI, coronary artery bypass graft (CABG), cerebrovascular accident (CVA). Among the 5167 patients with STEMI, MACCEs had occurred in 168 patients in the previous-angina group (14.9%) and 726 patients in the control group (18.0%) (HR, 0.76, 95% CI, 0.60-0.96, p=0.019) at the two-year (800-day) for clinical outcomes. Previous angina was associated with better clinical outcomes with respect to all-cause death (HR, 0.65, 95% CI, 0.44-0.96, p=0.029) and cardiac death (HR, 0.52, 95% CI, 0.31-0.84, p=0.008). Previous angina was a negative risk factor for adverse cardiac events. A previous history of angina predisposes a patient to a favorable outcome after acute myocardial infarction (AMI) in patients with DES implantation.

Patients with coronary artery disease after acute myocardial infarction: effects of continuous enrollment in a structured Disease Management Program on adherence to guideline-recommended medication, health care expenditures, and survival

OBJECTIVE

Acute myocardial infarction (AMI) carries increased risk of mortality and excess costs. Disease Management Programs (DMPs) providing guideline-recommended care for chronic diseases seem an intuitively appealing way to enhance health outcomes for patients with chronic conditions such as AMI. The aim of the study is to compare adherence to guideline-recommended medication, health care expenditures and survival of patients enrolled and not enrolled in the German DMP for coronary artery disease (CAD) after an AMI from the perspective of a third-party payer over a follow-up period of 3 years.

METHODS

The study is based on routinely collected data from a regional statutory health insurance fund (n = 15,360). A propensity score matching with caliper method was conducted. Afterwards guideline-recommended medication, health care expenditures, and survival between patients enrolled and not enrolled in the DMP were compared with generalized linear and Cox proportional hazard models.

RESULTS

The propensity score matching resulted in 3870 pairs of AMI patients previously and continuously enrolled and not enrolled in the DMP. In the 3-year follow-up period the proportion of days covered rates for ACE-inhibitors (60.95% vs. 58.92%), anti-platelet agents (74.20% vs. 70.66%), statins (54.18% vs. 52.13%), and β-blockers (61.95% vs. 52.64%) were higher in the DMP group. Besides that, DMP participants induced lower health care expenditures per day (€58.24 vs. €72.72) and had a significantly lower risk of death (HR: 0.757).

CONCLUSION

Previous and continuous enrollment in the DMP CAD for patients after AMI is a promising strategy as it enhances guideline-recommended medication, reduces health care expenditures and the risk of death.

Remote Ischemic Conditioning in Acute Myocardial Infarction and Shock States

Remote ischemic conditioning is the phenomenon whereby brief, nonlethal episodes of ischemia in one organ (such as a limb) protect a remote organ from ischemic necrosis induced by a longer duration of severe ischemia followed by reperfusion. This phenomenon has been reproduced by dozens of experimental laboratories and was shown to reduce the size of myocardial infarction in many but not all clinical studies. In one recent large clinical trial, remote ischemic conditioning induced by repetitive blood pressure cuff inflations on the arm did not reduce infarct size or improve clinical outcomes. This negative result may have been related in part to the overall success of early reperfusion and current adjunctive therapies, such as antiplatelet therapy, antiremodeling therapies, and low-risk patients, that may make it difficult to show any advantage of newer adjunctive therapies on top of existing therapies. One relevant area in which current outcomes are not as positive as in the treatment of heart attack is the treatment of shock, where mortality rates remain high. Recent experimental studies show that remote ischemic conditioning may improve survival and organ function in shock states, especially hemorrhagic shock and septic shock. In this study, we review the preclinical studies that have explored the potential benefit of this therapy for shock states and describe an ongoing clinical study.

Influence of Cardiovascular Risk Factors, Comorbidities, Medication Use and Procedural Variables on Remote Ischemic Conditioning Efficacy in Patients with ST-Segment Elevation Myocardial Infarction

Remote ischemic conditioning (RIC) confers cardioprotection in patients with ST-segment elevation myocardial infarction (STEMI). Despite intense research, the translation of RIC into clinical practice remains a challenge. This may, at least partly, be due to confounding factors that may modify the efficacy of RIC. The present review focuses on cardiovascular risk factors, comorbidities, medication use and procedural variables which may modify the efficacy of RIC in patients with STEMI. Findings of such efficacy modifiers are based on subgroup and post-hoc analyses and thus hold risk of type I and II errors. Although findings from studies evaluating influencing factors are often ambiguous, some but not all studies suggest that smoking, non-statin use, infarct location, area-at-risk of infarction, pre-procedural Thrombolysis in Myocardial Infarction (TIMI) flow, ischemia duration and coronary collateral blood flow to the infarct-related artery may influence on the cardioprotective efficacy of RIC. Results from the on-going CONDI2/ERIC-PPCI trial will determine any clinical implications of RIC in the treatment of patients with STEMI and predefined subgroup analyses will give further insight into influencing factors on the efficacy of RIC.

Electrocardiographic measures of ventricular repolarization dispersion and arrhythmic outcomes among ST elevation myocardial infarction patients with pre-infarction angina undergoing primary percutaneous coronary intervention

BACKGROUND

Arrhythmias are considered one of the major causes of death in ST elevation myocardial infarction (STEMI), particularly in the early in-hospital phase. Pre-infarction angina (PIA) has been suggested to have a protective role.

OBJECTIVES

To study the difference in acute electrocardiographic findings between STEMI patients with and without PIA and to assess the in-hospital arrhythmias in both groups.

MATERIAL AND METHODS

We prospectively enrolled 238 consecutive patients with STEMI. Patients were divided into two groups: those with or without PIA. ECG data recorded and analyzed included ST-segment resolution (STR) at 90 min, corrected QT interval (QTc) and dispersion (QTD), T-peak-to-T-end interval (Tp-Te), and dispersion and Tp-Te/QT ratio. In-hospital ventricular arrhythmias encountered in both groups were recorded. Predictors of in-hospital arrhythmias were assessed among different clinical and electrocardiographic parameters.

RESULTS

Of the 238 patients included, 42 (17%) had PIA and 196 (83%) had no PIA. Patients with PIA had higher rates of STR (p < 0.0001), while patients with no PIA had higher values of QTc (p = 0.006), QTD (p = 0.001), Tp-Te interval (p = 0.001), Tp-Te dispersion (p < 0.0001), and Tp-Te/QT ratio (p = 0.01) compared to those with angina preceding their incident infarction (PIA). This was reflected into significantly higher rates of in-hospital arrhythmias among patients with no PIA (20% vs. 7%, p = 0.04). Furthermore, longer Tp-Te interval and higher Tp-Te/QT ratio independently predicted in-hospital ventricular arrhythmias.

CONCLUSION

Pre-infarction angina patients had better electrocardiographic measures of repolarization dispersion and encountered significantly less arrhythmic events compared to patients who did not experience PIA.

Effect of ischemic preconditioning on cardiovascular outcomes in patients with symptomatic coronary artery disease: a cohort study

BACKGROUND

Despite the powerful myocardial protection of ischemic preconditioning (IP) observed in experimental studies, it remains a challenge to observe such protection in humans. Thus, the aim of this study was to evaluate the possible effects of IP on clinical outcomes in patients with coronary artery disease (CAD).

PATIENTS AND METHODS

In this cohort study, patients with multivessel CAD, preserved systolic ventricular function, and stable angina were prospectively selected. They underwent two sequential exercise stress tests (EST) to evaluate IP presence. IP was considered present if patients had an improvement in the time to the onset of 1.0-mm STsegment deviation in the second EST. The primary end point was the composite rate of cardiac death, nonfatal myocardial infarction, or revascularization during 1-year follow-up. Patients with (IP+) and without (IP-) the cardioprotective mechanism were compared regarding clinical end points.

RESULTS

A total of 229 patients completed EST and had IP evaluated: 165 (72%) were IP+ and 64 (28%) were IP - patients. Of these, 218 patients had complete follow-up. At 1-year, event-free survival regarding the primary end point was 95.5 versus 83.6% (P = 0.0024) and event-free survival regarding cardiac death or myocardial infarction was 99.4 versus 91.7% (P=0.0020), respectively, in IP + and IP - groups. The unadjusted hazard ratio (IP + /IP-) for the primary end point was 4.63 (1.52-14.08). After multivariate analysis, IP was still significantly associated with better clinical outcomes (P = 0.0025).

CONCLUSION

This data suggest that IP may contribute to better clinical outcomes in patients with ischemic heart disease.

Electrically-Induced Ventricular Fibrillation Alters Cardiovascular Function and Expression of Apoptotic and Autophagic Proteins in Rat Hearts

BACKGROUND

The pathological heart contractions, called arrhythmias, especially ventricular fibrillation (VF), are a prominent feature of many cardiovascular diseases leading to sudden cardiac death. The present investigation evaluates the effect of electrically stimulated VF on cardiac functions related to autophagy and apoptotic mechanisms in isolated working rat hearts.

METHODS

Each group of hearts was subjected to 0 (Control), 1, 3, or 10 min of spacing-induced VF, followed by 120 min of recovery period and evaluated for cardiac functions, including aortic flow (AF), coronary flow (CF), cardiac output (CO), stroke volume (SV), and heart rate (HR). Hearts were also evaluated for VF effects on infarcted zone magnitude and Western blot analysis was conducted on heart tissue for expression of the apoptotic biomarker cleaved-caspase-3 and the autophagy proteins: p62, P-mTOR/mTOR, LC3BII/LC3BI ratio, and Atg5-12 complexes.

RESULTS

Data revealed that VF induced degradation in AF, CF, CO, and SV, which prominently included-variable post-VF capacity for recovery of normal heart rhythm; increased extent of infarcted heart tissue; altered expression of cleaved-caspase-3 suggesting potential for VF-mediated amplification of apoptosis. VF influence on expression of p62, LC3BII/LC3BI, and Atg5-12 proteins was complex, possibly due to differential effects of VF-induced expression on proteins comprising the autophagic program.

CONCLUSIONS

VF was observed to cause time-dependent changes in autophagy processes, which with additional analysis under ongoing investigations, likely to yield novel therapeutic targets for the prevention of VF and sudden cardiac death.

Cortisol Response in Children After Second Cardiopulmonary Bypass

A surge in cortisol levels is seen after surgery with cardiopulmonary bypass (CPB). Based on evidence of attenuation of the cortisol response to repeated stress in other settings, we hypothesized that the magnitude of cortisol increase in children after a second exposure to CPB would be reduced. Serial cortisol levels were measured at three time points after each CPB: immediately (day 0), on the first morning (day 1), and second morning (day 2). Forty-six children underwent two surgeries with CPB during the study period. The mean age (standard deviation) at first and second surgery was 3.5 (6.3) months and 10.4 (9.9) months, respectively. Cortisol levels at the first surgery were 109 (105) µg/dl, 29 (62) µg/dl, and 17 (12) µg/dl on day 0, 1, and 2, respectively; similarly at second surgery, it was 61 (57) µg/dl on day 0 to 20 (16) µg/dl and 11 (10) µg/dl on day 1 and 2, respectively. After log-transformation and adjusting for time interval between surgeries, cortisol levels at the second surgery were lower by 42% on day 0 (p = 0.02), and 46% lower on day 2 (p = 0.02). A second exposure to CPB in children with congenital heart disease is associated with an attenuated cortisol release.

Prodromal angina and risk of 2-year cardiac mortality in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous intervention

We sought to investigate the prognostic significance of prodromal angina (PA) in unselected patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) and its additive predictive value to the GRACE score.We prospectively enrolled 3015 consecutive STEMI patients undergoing PPCI. Patients were divided in 2 groups according to the presence or absence of PA. Multivariable Cox regression was used to establish the relation to 2-year cardiac mortality of PA.The mean age of the study population was 68 (±14) years; 2178 patients (72%) were male. During follow-up, 395 (13%) patients died with 278 of these (9.2%) suffering from cardiac mortality. Kaplan-Meier estimates showed a survival rate of 95% and 87% for patients with PA and no PA, respectively (log rank test < 0.001). After multivariable analysis, patients with PA had still a lower risk of 2 years' cardiac mortality compared with patients without PA (adjusted hazard ratio = 0.50; 95% confidence interval [CI] 1.06-1.81, P = .001). Evaluation of net reclassification improvement showed that reclassification improved by 0.16% in case patients, whereas classification worsened in control patients by 1.08% leading to a net reclassification improvement of -0.93% (95% CI: -0.98, -0.88).In patients with STEMI undergoing PPCI the presence of PA is independently associated with a lower risk of 2-year cardiac mortality. However, the incorporation of this variable to the GRACE score slightly worsened the classification of risk. Accordingly, it seems unlikely that the evaluation of PA may be useful in clinical practice.

Relation of coronary culprit lesion morphology determined by optical coherence tomography and cardiac outcomes to preinfarction angina in patients with acute myocardial infarction

BACKGROUND

While preinfarction angina pectoris (pre-IA) is recognized as favorable effects on acute myocardial infarction (AMI), the detail has not been fully investigated. The aims of the current study were to clarify patient characteristics, lesion morphologies determined by optical coherence tomography (OCT), and cardiac outcomes related to pre-IA in patients with AMI.

METHODS

Clinical data and outcomes were compared between AMI patients with pre-IA (pre-IA group, n = 507) and without pre-IA (non-pre-IA group, n = 653). Angiography and OCT findings were analyzed in patients with pre-intervention OCT and compared between groups of pre-IA (n = 219) and non-pre-IA (n = 269).

RESULTS

ST-segment elevation myocardial infarction (61% vs. 75%, p < 0.001) and cardiogenic shock (8% vs. 14%, p = 0.001) were less prevalent in pre-IA group. Peak creatine kinase-MB levels were lower in pre-IA group (median 83 IU/mL vs. 126 IU/mL, p < 0.001). In pre-intervention coronary angiography findings, initial TIMI flow grade 0/1 (43% vs. 56%, p = 0.019) and Rentrop collateral circulation 0/1 (69% vs. 79%, p = 0.018) were less frequently observed in pre-IA than in non-pre-IA patients. In post-thrombectomy OCT images, plaque rupture (39% vs. 56%, p = 0.003) and red thrombi (42% vs. 54%, p = 0.027) were also less frequently observed in pre-IA group. Kaplan-Meier estimate survival curves showed that cardiac death at 12-months was lower in pre-IA group than in non-pre-IA group (6.9% vs. 10.1%, p = 0.036).

CONCLUSIONS

Patients with pre-IA had less severe AMI on admission, smaller infarction size, and more favorable long-term survival, which may be caused by difference of lesion morphology between patients with and without pre-IA.

Clinical translation of myocardial conditioning

Rapid admission and acute interventional treatment combined with modern antithrombotic pharmacologic therapy have improved outcomes in patients with ST elevation myocardial infarction. The next major target to further advance outcomes needs to address ischemia-reperfusion injury, which may contribute significantly to the final infarct size and hence mortality and postinfarction heart failure. Mechanical conditioning strategies including local and remote ischemic pre-, per-, and postconditioning have demonstrated consistent cardioprotective capacities in experimental models of acute ischemia-reperfusion injury. Their translation to the clinical scenario has been challenging. At present, the most promising mechanical protection strategy of the heart seems to be remote ischemic conditioning, which increases myocardial salvage beyond acute reperfusion therapy. An additional aspect that has gained recent focus is the potential of extended conditioning strategies to improve physical rehabilitation not only after an acute ischemia-reperfusion event such as acute myocardial infarction and cardiac surgery but also in patients with heart failure. Experimental and preliminary clinical evidence suggests that remote ischemic conditioning may modify cardiac remodeling and additionally enhance skeletal muscle strength therapy to prevent muscle waste, known as an inherent component of a postoperative period and in heart failure. Blood flow restriction exercise and enhanced external counterpulsation may represent cardioprotective corollaries. Combined with exercise, remote ischemic conditioning or, alternatively, blood flow restriction exercise may be of aid in optimizing physical rehabilitation in populations that are not able to perform exercise practice at intensity levels required to promote optimal outcomes.

The pathophysiology of acute myocardial infarction and strategies of protection beyond reperfusion: a continual challenge

The incidence of ST segment elevation myocardial infarction (STEMI) has decreased over the last two decades in developed countries, but mortality from STEMI despite widespread access to reperfusion therapy is still substantial as is the development of heart failure, particularly among an expanding older population. In developing countries, the incidence of STEMI is increasing and interventional reperfusion is often not available. We here review the pathophysiology of acute myocardial infarction and reperfusion, notably the temporal and spatial evolution of ischaemic and reperfusion injury, the different modes of cell death, and the resulting coronary microvascular dysfunction. We then go on to briefly characterize the cardioprotective phenomena of ischaemic preconditioning, ischaemic postconditioning, and remote ischaemic conditioning and their underlying signal transduction pathways. We discuss in detail the attempts to translate conditioning strategies and drug therapy into the clinical setting. Most attempts have failed so far to reduce infarct size and improve clinical outcomes in STEMI patients, and we discuss potential reasons for such failure. Currently, it appears that remote ischaemic conditioning and a few drugs (atrial natriuretic peptide, exenatide, metoprolol, and esmolol) reduce infarct size, but studies with clinical outcome as primary endpoint are still underway.

Repeated ischaemic preconditioning: a novel therapeutic intervention and potential underlying mechanisms

What is the topic of this review? This review discusses the effects of repeated exposure of tissue to ischaemic preconditioning on cardiovascular function, the attendant adaptations and their potential clinical relevance. What advances does it highlight? We discuss the effects of episodic exposure to ischaemic preconditioning to prevent and/or attenuate ischaemic injury and summarize evidence pertaining to improvements in cardiovascular function and structure. Discussion is provided regarding the potential mechanisms that contribute to both local and systemic adaptation. Findings suggest that clinical benefits result from both the prevention of ischaemic events and the attenuation of their consequences. Ischaemic preconditioning (IPC) refers to the phenomenon whereby short periods of cyclical tissue ischaemia confer subsequent protection against ischaemia-induced injury. As a consequence, IPC can ameliorate the myocardial damage following infarction and can reduce infarct size. The ability of IPC to confer remote protection makes IPC a potentially feasible cardioprotective strategy. In this review, we discuss the concept that repeated exposure of tissue to IPC may increase the 'dose' of protection and subsequently lead to enhanced protection against ischaemia-induced myocardial injury. This may be relevant for clinical populations, who demonstrate attenuated efficacy of IPC to prevent or attenuate ischaemic injury (and therefore myocardial infarct size). Furthermore, episodic IPC facilitates repeated exposure to local (e.g. shear stress) and systemic stimuli (e.g. hormones, cytokines, blood-borne substances), which may induce improvement in vascular function and health. Such adaptation may contribute to prevention of cardio- and cerebrovascular events. The clinical benefits of repeated IPC may, therefore, result from both the prevention of ischaemic events and the attenuation of their consequences. We provide an overview of the literature pertaining to the impact of repeated IPC on cardiovascular function, related to both local and remote adaptation, as well as potential clinical implications.

Role of Calcium Channel Blockers in Myocardial Preconditioning

Coronary heart disease is the leading cause of mortality and morbidity worldwide. The effects of coronary heart disease are usually attributable to the detrimental effects of acute myocardial ischaemia-reperfusion injury. Newer strategies such as ischaemic or pharmacological preconditioning have been shown to condition the myocardium to ischaemia-reperfusion injury and thus reduce the final infarct size. This review investigates the role of calcium channel blockers in myocardial preconditioning. Additionally, special attention is given to nicorandil whose mechanism of action may be associated with the cardioprotective effects of preconditioning. There are still many uncertainties in understanding the role of these agents in preconditioning, but future research in this direction will certainly help reduce coronary heart disease.

Ischemic Conditioning Attenuates Platelet-Mediated Thrombosis

Data obtained in both preclinical models and humans have revealed that the favorable cardiac consequences of ischemic conditioning extend beyond a direct effect on the cardiomyocyte. In the current review, we summarize our as-yet limited understanding of the complex relationships between ischemic conditioning, platelet activation–aggregation, and cardioprotection.

Remote Ischemic Conditioning for Patients With STEMI

ST-segment elevation myocardial infarction (STEMI) remains a leading cause of death and morbidity, despite declining incidence and improved short-term outcome in many countries. Although mortality declines in developed countries with easy and fast access to optimized treatment, development of heart failure often remains a challenge in survivors and still approaches 10% at 1 year. Rapid admission and acute interventional treatment combined with modern antithrombotic pharmacologic therapy frequently establish complete reperfusion and acutely stabilize the patient, but the reperfusion itself adds further to the damage in the myocardium compromising the long-term outcome. Reperfusion injury is believed to be a significant-if not the dominant-contributor to the net injury resulting from STEMI and has become a major focus of research in recent years. Despite a plethora of pharmacological and mechanical interventions showing consistent reduction of reperfusion injury in experimental models, translation into a clinical setting has been challenging. In patients, attempts to modify reperfusion injury by pharmacological strategies have largely been unsuccessful, and focus is increasingly directed toward mechanical modalities. Remote ischemic conditioning of the heart is achieved by repeated brief interruption of the blood supply to a distant part of the body, most frequently the arm. At present, remote ischemic conditioning is the most promising adjuvant therapy to reduce reperfusion injury in patients with STEMI. In this review, we discuss the results of clinical trials investigating the effect of remote ischemic conditioning in patients admitted with STEMI and potential reasons for its apparent superiority to current pharmacologic adjuvant therapies.

Comparison of Clinical Characteristics and Outcomes of Patients With Versus Without Diabetes Mellitus and With Versus Without Angina Pectoris (from the Duke Databank for Cardiovascular Disease)

Angina pectoris (AP) has different prognostic implications in various populations. Patients with diabetes mellitus (DM) may experience neuropathy such that AP may not be perceived in the setting of coronary artery disease (CAD). The prognostic utility of AP in DM patients with CAD is not well known. We analyzed patients with CAD who underwent coronary angiography at Duke University from 2002 to 2011 and compared patients with and without AP within the previous 6 weeks stratified by DM status. We used multivariable Cox regression to assess the association between AP and the outcomes of cardiovascular (CV) hospitalization/revascularization, all-cause mortality/myocardial infarction/revascularization, and all-cause mortality. Of 17,211 patients with CAD, 5,284 (31%) had DM and AP was present in 69% of DM and 67% of non-DM. After risk adjustment, the risk of CV hospitalization/revascularization and all-cause mortality/myocardial infarction/revascularization in patients with and without AP was similar regardless of DM status (all p ≥0.05). In patients with or without DM, AP was associated with lower all-cause mortality compared with no AP (adjusted hazard ratio 0.89, 95% confidence interval 0.82 to 0.97, p = 0.005 for DM patients). The relation between AP status and clinical outcomes was not dependent on DM status (all interaction p >0.10). In conclusion, in patients with CAD, AP was associated with similar risk for CV hospitalization and revascularization and lower all-cause mortality compared with patients without AP regardless of DM status. Future studies are needed to assess whether these findings are related to increased severity of disease in those without AP or whether AP leads to differential management that improves survival.

Rat Models of Ventricular Fibrillation Following Acute Myocardial Infarction

A number of animal models have been designed in order to unravel the underlying mechanisms of acute ischemia-induced arrhythmias and to test compounds and interventions for antiarrhythmic therapy. This is important as acute myocardial infarction (AMI) continues to be the major cause of sudden cardiac death, and we are yet to discover safe and effective treatments of the lethal arrhythmias occurring in the acute setting. Animal models therefore continue to be relevant for our understanding and treatment of acute ischemic arrhythmias. This review discusses the applicability of the rat as a model for ventricular arrhythmias occurring during the acute phase of AMI. It provides a description of models developed, advantages and disadvantages of rats, as well as an overview of the most important interventions investigated and the relevance for human pathophysiology.

Predictors of no- reflow during primary angioplasty for acute myocardial infarction, from Medical College Hospital, Trivandrum

Background

Primary angioplasty (PCI) for acute myocardial infarction is associated with no-reflow phenomenon, in about 5–25% of cases. Here we analysed the factors predicting no reflow .

Methods

This was a case control study of consecutive patients with acute myocardial infarction who underwent Primary PCI from August 2014 to February 2015.

Results

Of 181 patients who underwent primary PCI, 47 (25.9%) showed an angiographic no-reflow phenomenon. The mean age was 59.19 ± 10.25 years and females were 11%.

Univariate predictors of no reflow were age >60 years (OR = 6.146, 95%CI 2.937–12.86, P = 0<0.001), reperfusion time >6 h (OR = 21.94, 95%CI 9.402–51.2, P = < 0.001), low initial TIMI flow (≤1) (OR = 12.12, 95%CI 4.117–35.65, P < 0.001), low initial TMPG flow (≤1) (OR = 36.19, 95%CI 4.847–270.2, P < 0.001) a high thrombus burden (OR = 11.04,95%CI 5.124–23.8, P < 0.001), a long target lesion (OR = 8.54, 95%CI 3.794–19.23, P < 0.001), Killip Class III/IV(OR = 2.937,95%CI 1.112–7.756,P = 0.025) and overlap stenting(OR = 3.733,95%CI 1.186–11.75,P = 0.017).

Multiple stepwise logistic regression analysis predictors were: longer reperfusion time > 6 h (OR = 13.844, 95%CI 3.214–59.636, P = <0.001), age >60 years (OR = 8.886, 95%CI 2.145–36.80, P = 0.003), a long target lesion (OR = 8.637, 95%CI 1.975–37.768, P = 0.004), low initial TIMI flow (≤1) (OR = 20.861, 95%CI 1.739–250.290, P = 0.017).

Conclusions

It is important to minimize trauma to the vessel, avoid repetitive balloon dilatations use direct stenting and use the shortest stent if possible.

Angina and Its Management

Angina pectoris is defined as substernal chest pain, pressure, or discomfort that is typically exacerbated by exertion and/or emotional stress, lasts greater than 30 to 60 seconds, and is relieved by rest and nitroglycerin. There are approximately 10 million people in the United States who have angina, and there are over 500 000 cases diagnosed per year. Several studies now show that angina itself is a predictor of major adverse cardiac events. In addition, angina is a serious morbidity that impedes quality of life and should be treated. In the United States, pharmacologic therapy for angina includes β-blockers, nitrates, calcium channel blockers, and the late sodium current blocker ranolazine. In other countries, additional pharmacologic agents include trimetazidine, ivabradine, nicorandil, fasudil, and others. Revascularization is indicated in certain high-risk individuals and also has been shown to improve angina. However, even after revascularization, a substantial percentage of patients return with recurrent or continued angina, requiring newer and better therapies. Treatment for refractory angina not amenable to usual pharmacologic therapies or revascularization procedures, includes enhanced external counterpulsation, transmyocardial revascularization, and stem cell therapy. Angina continues to be a significant cause of morbidity. Therapy should be geared not only to treating the risk factors for atherosclerotic disease and improving survival but should also be aimed at eliminating or reducing the occurrence of angina and improving the ability of patients to be active.

State of the Science of Cardioprotection: Challenges and Opportunities— Proceedings of the 2010 NHLBI Workshop on Cardioprotection

The National Heart, Lung, and Blood Institute convened a Workshop on September 20-21, 2010, “New Horizons in Cardioprotection,” to identify future research directions for cardioprotection against ischemia and reperfusion injury. Since the early 1970s, there has been evidence that the size of a myocardial infarction could be altered by various interventions. Early coronary artery reperfusion has been an intervention that consistently reduces myocardial infarct size in animal models as well as humans. Most cardiologists agree that the best way to treat acute ST-segment elevation myocardial infarction is to reperfuse the infarct artery as soon as possible and to keep the infarct artery patent. In general, stenting is superior to angioplasty, which is superior to thrombolysis. There is no accepted adjunctive therapy to acutely limit myocardial infarct size along with reperfusion that is routinely used in clinical practice. In the Kloner experimental laboratory, some adjunctive therapies have reproducibly limited infarct size (regional hypothermia, preconditioning, cariporide, combinations of the above, remote preconditioning, certain adenosine agonists, and late sodium current blockade). In clinical trials, a host of pharmacologic adjunctive therapies have failed to either reduce infarct size or improve clinical outcome. Potential reasons for the failure of these trials are discussed. However, some adjunctive therapies have shown promise in data subanalyses or subpopulations of clinical trials (adenosine, therapeutic hypothermia, and hyperoxemic reperfusion) or in small clinical trials (atrial natriuretic peptide, ischemic postconditioning, and cyclosporine, the mitochondrial permeability transition pore inhibitor). A recent clinical trial with remote conditioning induced by repetitive inflation of a brachial artery cuff begun prior to hospitalization showed promise in improving myocardial salvage and there are several reports in the cardiothoracic literature, suggesting that remote preconditioning protects hearts during surgery. Thus, in 2011, there is hope that applying some of the body’s own conditioning mechanisms may provide protection against ischemic damage.

Influence of preinfarction angina and coronary collateral blood flow on the efficacy of remote ischaemic conditioning in patients with ST segment elevation myocardial infarction: post hoc subgroup analysis of a randomised controlled trial

OBJECTIVES

Remote ischaemic conditioning (RIC) confers cardioprotection in patients with ST segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). We investigated whether preinfarction angina and coronary collateral blood flow (CCBF) to the infarct-related artery modify the efficacy of RIC.

DESIGN

Post hoc subgroup analysis of a randomised controlled trial.

PARTICIPANTS

A total of 139 patients with STEMI randomised to treatment with pPCI or RIC+pPCI.

INTERVENTIONS

RIC was performed prior to pPCI as four cycles of 5 min upper arm ischaemia and reperfusion with a blood pressure cuff.

PRIMARY OUTCOME MEASURE

Myocardial salvage index (MSI) assessed by single-photon emission computerised tomography. We evaluated the efficacy of RIC in subgroups of patients with or without preinfarction angina or CCBF.

RESULTS

Of 139 patients included in the study, 109 had available data for preinfarction angina status and 54 had preinfarction angina. Among 83 patients with Thrombolysis In Myocardial Infarction flow 0/1 on arrival, 43 had CCBF. Overall, RIC+pPCI increased median MSI compared with pPCI alone (0.75 vs 0.56, p=0.045). Mean MSI did not differ between patients with and without preinfarction angina in either the pPCI alone (0.58 and 0.57; 95% CI -0.17 to 0.19, p=0.94) or the RIC+pPCI group (0.66 and 0.69; 95% CI -0.18 to 0.10, p=0.58). Mean MSI did not differ between patients with and without CCBF in the pPCI alone group (0.51 and 0.55; 95% CI -0.20 to 0.13, p=0.64), but was increased in patients with CCBF versus without CCBF in the RIC+pPCI group (0.75 vs 0.58; 95% CI 0.03 to 0.31, p=0.02; effect modification from CCBF on the effect of RIC on MSI, p=0.06).

CONCLUSIONS

Preinfarction angina did not modify the efficacy of RIC in patients with STEMI undergoing pPCI. CCBF to the infarct-related artery seems to be of importance for the cardioprotective efficacy of RIC.

TRIAL REGISTRATION NUMBER

NCT00435266, Post-results.

EGLN1 Inhibition and Rerouting of α-Ketoglutarate Suffice for Remote Ischemic Protection

Ischemic preconditioning is the phenomenon whereby brief periods of sublethal ischemia protect against a subsequent, more prolonged, ischemic insult. In remote ischemic preconditioning (RIPC), ischemia to one organ protects others organs at a distance. We created mouse models to ask if inhibition of the alpha-ketoglutarate (αKG)-dependent dioxygenase Egln1, which senses oxygen and regulates the hypoxia-inducible factor (HIF) transcription factor, could suffice to mediate local and remote ischemic preconditioning. Using somatic gene deletion and a pharmacological inhibitor, we found that inhibiting Egln1 systemically or in skeletal muscles protects mice against myocardial ischemia-reperfusion (I/R) injury. Parabiosis experiments confirmed that RIPC in this latter model was mediated by a secreted factor. Egln1 loss causes accumulation of circulating αKG, which drives hepatic production and secretion of kynurenic acid (KYNA) that is necessary and sufficient to mediate cardiac ischemic protection in this setting.

Serum Fatty Acids, Traditional Risk Factors, and Comorbidity as Related to Myocardial Injury in an Elderly Population with Acute Myocardial Infarction

Background. Epidemiological and randomized clinical trials indicate that marine polyunsaturated n-3 fatty acids (n-3 PUFAs) may have cardioprotective effects. Aim. Evaluate the associations between serum fatty acid profile, traditional risk factors, the presence of cardiovascular diseases (CVD), and peak Troponin T (TnT) levels in elderly patients with an acute myocardial infarction (AMI). Materials and Methods. Patients (n = 299) consecutively included in the ongoing Omega-3 fatty acids in elderly patients with myocardial infarction (OMEMI) trial were investigated. Peak TnT was registered during the hospital stay. Serum fatty acid analysis was performed 2–8 weeks later. Results. No significant correlations between peak TnT levels and any of the n-3 PUFAs were observed. However, patients with a history of atrial fibrillation had significantly lower docosahexaenoic acid levels than patients without. Significantly lower peak TnT levels were observed in patients with a history of hyperlipidemia, angina, MI, atrial fibrillation, intermittent claudication, and previous revascularization (all p < 0.02). Conclusions. In an elderly population with AMI, no association between individual serum fatty acids and estimated myocardial infarct size could be demonstrated. However, a history of hyperlipidemia and the presence of CVD were associated with lower peak TnT levels, possibly because of treatment with cardioprotective medications.

Clinical Profiles Related to Timing of Death, Including In-Hospital Deaths Before Admission, in Patients With ST-Elevation Myocardial Infarction

Patients with ST-elevation myocardial infarction (STEMI) who die in hospital before inpatient admission are generally not included in clinical studies and registries, and the clinical profiles of patients who die earlier versus later are not well defined. We aimed to characterize all patients with STEMI who arrived at emergency departments in the province of Quebec (Canada) based on inpatient admission status and when they died. All patients who presented with symptoms and core laboratory-confirmed STEMI or left bundle branch block during 6 months in 82 hospitals in Quebec were included. Death certificates were used to identify nonadmitted deaths. Of the 2017 patients with STEMI, 340 (16.9%) died within 1 year. Of the latter, 63 (18.5%) were nonadmitted deaths (group A), 179 (52.6%) were deaths after admission but within 30 days (group B), and 98 (28.8%) were deaths after 30 days to 1 year (group C). Group A was younger and most often hemodynamically unstable, followed for both features by B then C. Earliest presentation from symptom onset and most frequent ambulance use were found in group A, followed by B, then C. Presenting electrocardiogram (ECG) features were most severe in A, then B, then C (more arrhythmias, more anterior STEMI, more leads with ST elevation, and higher ST elevation). Patients who died earliest had the least frequency of previous myocardial infarction, coronary revascularization, vascular disease, and heart failure, and the least noncardiac co-morbidity. In conclusion, patients with STEMI dying in hospital before inpatient admission contributed substantially to overall STEMI mortality. Although dying patients who presented earlier had severer presenting clinical profiles, they were paradoxically younger and had less co-morbidity. Previous co-morbidities may favor adaptive protective mechanisms on initial presentation with STEMI.

Management of Refractory Angina Pectoris

With improvements in survival from coronary artery disease (CAD) and an ageing population, refractory angina (RA) is becoming an increasingly common clinical problem facing clinicians in routine clinical practice. These patients experience chronic symptoms in the context of CAD, characterised by angina-type pain, which is uncontrolled despite optimal pharmacological, interventional and surgical therapy. Although mortality rates are no worse in this cohort, patients experience a significantly impaired quality of life with disproportionately high utilisation of healthcare services. It has been increasingly recognised that the needs of RA patients are multifactorial and best provided by specialist multi-disciplinary units. In this review, we consider the variety of therapies available to clinicians in the management of RA and discuss the promise of novel treatments.

Impaired PI3K/Akt Signaling as a Potential Cause of Failure to Precondition Rat Hearts Under Conditions of Simulated Hyperglycemia

The aim of the study was to evaluate the impact of simulated acute hyperglycemia (HG) on PI3K/Akt signaling in preconditioned and non-preconditioned isolated rat hearts perfused with Krebs-Henseleit solution containing normal (11 mmol/l) or elevated (22 mmol/l) glucose subjected to ischemia-reperfusion. Ischemic preconditioning (IP) was induced by two 5-min cycles of coronary occlusion followed by 5-min reperfusion. Protein levels of Akt, phosphorylated (activated) Akt (P-Akt), as well as contents of BAX protein were assayed (Western blotting) in cytosolic fraction of myocardial tissue samples taken prior to and after 30-min global ischemia and 40-min reperfusion. In “normoglycemic” conditions (NG), IP significantly increased P-Akt at the end of long-term ischemia, while reperfusion led to its decrease together with the decline of BAX levels as compared to non-preconditioned hearts. On the contrary, under HG conditions, P-Akt tended to decline in IP-hearts after long-term ischemia, and it was significantly higher after reperfusion than in non-preconditioned controls. No significant influence of IP on BAX levels at the end of I/R was observed under HG conditions. It seems that high glucose may influence IP-induced activation of Akt and its downstream targets, as well as maintain persistent Akt activity that may be detrimental for the heart under above conditions.

Association Between Preinfarction Angina and Angiographic Findings in Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

The association between preinfarction angina and angiographic findings has not been elucidated in patients with non-ST-segment elevation myocardial infarction (NSTEMI).

HYPOTHESIS

Patients with preinfarction angina have favorable angiographic findings.

METHODS

This retrospective study analyzed 481 patients who underwent coronary angiography within 5 days of presenting NSTEMI. Preinfarction angina was defined as experiencing ≥1 chest-pain episode within 7 days prior to admission. Infarct size was measured as the peak cardiac troponin I (cTnI) level, and large myocardial infarction (MI) was defined as a peak cTnI level >85th percentile value in the study population. Infarct-related artery (IRA) patency was defined as Thrombolysis In Myocardial Infarction grade 2 or 3 flow. Clinical and angiographic characteristics and in-hospital mortality were compared between patients with and without preinfarction angina.

RESULTS

Among 481 patients, 200 (42%) had preinfarction angina. Preinfarction angina was associated with smaller infarct size, indicated by lower peak cTnI levels (P = 0.006) and lower incidence of large MI (P = 0.02), and IRA patency (P = 0.03). There was no significant difference in in-hospital mortality. On multivariate analysis, both preinfarction angina (odds ratio: 0.53, 95% confidence interval: 0.29-0.94, P = 0.03) and IRA patency (odds ratio: 0.30, 95% confidence interval: 0.17-0.52, P < 0.001) were independent negative predictors of large MI.

CONCLUSION

Our study demonstrates that preinfarction angina is a predictor of smaller infarct size and infarct-related artery patency in NSTEMI patients, suggesting that NSTEMI patients presenting without preinfarction angina are at increased risk of developing a large MI.

Ischaemia change with revascularisation versus medical therapy in reduced ejection fraction

Objective

Nuclear imaging data demonstrate that revascularisation leads to favourable effects on ischaemia burden and improved outcomes compared with medical therapy (MT). In patients with heart failure (HF), the effects of MT versus revascularisation on ischaemia change and its independent prognostic significance requires investigation.

Methods

From the Duke Databank, we performed a retrospective analysis of 278 consecutive patients with coronary artery disease (CAD) and ejection fraction (EF) ≤40%, who underwent 2 serial myocardial perfusion scans between 1993 and 2009. Ischaemia change was calculated for patients undergoing MT alone, or revascularisation. Cox proportional hazards regression modelling was used to identify factors associated with death/myocardial infarction (MI).

Results

The magnitude of ischeamia reduction was greater with revascularisation than with MT alone (median change of −6% vs 0%, p<0.001). With revascularisation, more patients experienced ≥5% ischaemia reduction compared with MT (52% vs 25%, p<0.01) and a similar percentage experienced ≥5% ischaemia worsening (13% vs 18%, p=0.37). After risk adjustment, ≥5% ischaemia worsening was associated with decreased death/MI (HR=0.58; 95% CI 0.36 to 0.96).

Conclusions

In patients with HF with CAD, revascularisation improves long-term ischaemia burden compared with MT. Ischaemia worsening on nuclear imaging was associated with reduced risk of death/MI, potentially related to development of ischaemic viable myocardium as opposed to scar tissue.

Role of Endogenous Opioid System in Ischemic-Induced Late Preconditioning

BACKGROUND

Opioid receptors (OR) are involved in myocardial late preconditioning (LPC) induced by morphine and δ1-opioid receptor (δ1-OR) agonists. The role of OR in ischemic-induced LPC is unknown. We investigated whether 1) OR are involved in the trigger and/or mediation phase of LPC and 2) a time course effect on the expression of different opioid receptors and their endogenous ligands exists.

METHODS

Male Wistar rats were randomly allocated to four groups (each group n = 8). Awake animals were ischemic preconditioned by a 5 minutes coronary occlusion. 24 hours later, anesthetized animals underwent 25 minutes coronary occlusion followed by 2 hours of reperfusion. The role of OR was investigated by treatment with intraperitoneal naloxone (Nal) 10 minutes prior to LPC (Nal-LPC; trigger phase) or 10 min prior to sustained ischemia (LPC-Nal; mediation phase).

RESULTS

LPC reduced infarct size from 61±10% in controls to 25±9% (P<0.001). Naloxone during trigger or mediation phase completely abolished LPC-induced cardioprotection (59±9% and 62±9%; P<0.001 vs. LPC). 8, 12 and 24 hours after the ischemic stimulus, expression of δ-OR in the heart was increased, whereas μ-opioid receptor (μ-OR) and κ-opioid receptor (κ-OR) were not. Plasma concentrations of β-endorphin and leu-enkephalin but not dynorphin were increased by LPC.

CONCLUSION

Ischemic LPC is triggererd and mediated by OR. Expression of δ-OR and plasma levels of endogenous opioid peptides are increased after ischemic LPC.