Prospective temporal analysis of the onset of preinfarction angina versus outcome: an ancillary study in TIMI-9B

Interaction of Cardiovascular Nonmodifiable Risk Factors, Comorbidities and Comedications With Ischemia/Reperfusion Injury and Cardioprotection by Pharmacological Treatments and Ischemic Conditioning

Preconditioning, postconditioning, and remote conditioning of the myocardium enhance the ability of the heart to withstand a prolonged ischemia/reperfusion insult and the potential to provide novel therapeutic paradigms for cardioprotection. While many signaling pathways leading to endogenous cardioprotection have been elucidated in experimental studies over the past 30 years, no cardioprotective drug is on the market yet for that indication. One likely major reason for this failure to translate cardioprotection into patient benefit is the lack of rigorous and systematic preclinical evaluation of promising cardioprotective therapies prior to their clinical evaluation, since ischemic heart disease in humans is a complex disorder caused by or associated with cardiovascular risk factors and comorbidities. These risk factors and comorbidities induce fundamental alterations in cellular signaling cascades that affect the development of ischemia/reperfusion injury and responses to cardioprotective interventions. Moreover, some of the medications used to treat these comorbidities may impact on cardioprotection by again modifying cellular signaling pathways. The aim of this article is to review the recent evidence that cardiovascular risk factors as well as comorbidities and their medications may modify the response to cardioprotective interventions. We emphasize the critical need for taking into account the presence of cardiovascular risk factors as well as comorbidities and their concomitant medications when designing preclinical studies for the identification and validation of cardioprotective drug targets and clinical studies. This will hopefully maximize the success rate of developing rational approaches to effective cardioprotective therapies for the majority of patients with multiple comorbidities. SIGNIFICANCE STATEMENT: Ischemic heart disease is a major cause of mortality; however, there are still no cardioprotective drugs on the market. Most studies on cardioprotection have been undertaken in animal models of ischemia/reperfusion in the absence of comorbidities; however, ischemic heart disease develops with other systemic disorders (e.g., hypertension, hyperlipidemia, diabetes, atherosclerosis). Here we focus on the preclinical and clinical evidence showing how these comorbidities and their routine medications affect ischemia/reperfusion injury and interfere with cardioprotective strategies.

Percutaneous Myocardial Revascularization in Late-Presenting Patients With STEMI

BACKGROUND

The optimal management of patients with ST-segment elevation myocardial infarction (STEMI) presenting late->12 hours following symptom onset-is still under debate.

OBJECTIVES

The purpose of this study was to describe characteristics, temporal trends, and impact of revascularization in a large population of latecomer STEMI patients.

METHODS

The authors analyzed the data of 3 nationwide observational studies from the FAST-MI (French Registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction) program, conducted over a 1-month period in 2005, 2010, and 2015. Patients presenting between 12 and 48 hours after symptom onset were classified as latecomers.

RESULTS

A total of 6,273 STEMI patients were included in the 3 cohorts, 1,169 (18.6%) of whom were latecomers. After exclusion of patients treated with fibrinolysis and patients deceased within 2 days after admission, 1,077 patients were analyzed, of whom 729 (67.7%) were revascularized within 48 hours after hospital admission. At 30-day follow-up, all-cause death rate was significantly lower among revascularized latecomers (2.1% vs 7.2%; P < 0.001). After a median follow-up of 58 months, the rate of all-cause death was 30.4 (95% CI: 25.7-35.9) per 1,000 patient-years in the revascularized latecomers group vs 78.7 (95% CI: 67.2-92.3) per 1,000 patient-years in the nonrevascularized latecomers group (P < 0.001). In multivariate analysis, revascularization of latecomer STEMI patients was independently associated with a significant reduction of mortality occurrence during follow-up (HR: 0.65 [95% CI: 0.50-0.84]; P = 0.001).

CONCLUSIONS

Coronary revascularization of latecomer STEMI patients is associated with better short and long-term clinical outcomes.

Diagnosis and Management of Late-presentation ST-elevation Myocardial Infarction and Complications

The incidence of late presentation of myocardial infarction varies between 8.5% and 40%. Late revascularization of an infarct-related artery may limit infarct size and remodeling, reduce electrical instability, and may provide supplemental blood supply to that area via collaterals. Randomized clinical trials have shown a benefit of revascularization in symptomatic and hemodynamically unstable latecomers. Image stress testing can be beneficial to guide management of asymptomatic late presenters. Higher rates of myocardial infarction complications occur with late presentations, so a high level of suspicion is required for early diagnosis. Surgical repair remains the gold standard for management of mechanical complications.

Patient delay and benefit of timely reperfusion in ST-segment elevation myocardial infarction

Background

In patients with ST-segment elevation myocardial infarction (STEMI), it is unknown how patient delay modulates the beneficial effects of timely reperfusion.

Aims

To assess the prognostic significance of a contact-to-balloon time of less than 90 min on in-hospital mortality in different categories of symptom-onset-to-first-medical-contact (S2C) times.

Methods

A total of 20 005 consecutive patients from the Feedback Intervention and Treatment Times in ST-segment Elevation Myocardial Infarction (FITT-STEMI) programme treated with primary percutaneous coronary intervention (PCI) were included.

Results

There were 1554 deaths (7.8%) with a J-shaped relationship between mortality and S2C time. Mortality was 10.0% in patients presenting within 1 hour, and 4.9%, 6.0% and 7.3% in patient groups with longer S2C intervals of 1–2 hours, 2–6 hours and 6–24 hours, respectively. Patients with a short S2C interval of less than 1 hour (S2C<60 min) had the highest survival benefit from timely reperfusion with PCI within 90 min (OR 0.27, 95% CI 0.23 to 0.31, p<0.0001) as compared with the three groups with longer S2C intervals of 1 hour<S2C≤2 hours (OR 0.44, 95% CI 0.33 to 0.59, p<0.0001), 2 hours<S2C≤6 hours (OR 0.49, 95% CI 0.38 to 0.64, p<0.0001) and 6 hours<S2C≤24 hours (OR 0.42, 95% CI 0.30 to 0.58, p<0.0001).

Conclusions

Timely reperfusion with a contact-to-balloon time of less than 90 min is most effective in patients presenting with short S2C intervals of less than 1 hour, but has also beneficial effects in patients with S2C intervals of up to 24 hours.

Trial registration number

NCT00794001.

Prior angina reduces ıschemic mitral regurgitation in patients with ST-Elevation myocardial ınfarction, role of ıschemic preconditioning

Mitral regurgitation may develop due to left ventricular (LV) remodeling within 3 months following acute myocardial infarction (AMI) and is called ischemic mitral regurgitation (IMR). Ischemic preconditioning (IPC) has been reported as the most important mechanism of the association between prior angina and the favorable outcome. The aim of this study was to investigate the effect of prior angina on the development and severity of IMR at 3rd month in patients with ST elevation MI (STEMI). Fourty five (45) patients admitted with STEMI and at least mild IMR, revascularized by PCI were enrolled. According to presence of prior angina within 72 h before STEMI, patients were then divided into two groups as angina (+) (n:26; 58%) and angina (-) (n:19; 42%). All patients underwent 2D transthoracic echocardiography at 1st, 3rd days and 3rd month. IMR was evaluated by proximal isovelocity surface area (PISA) method: PISA radius (PISA-r), effective regurgitant orifice area (EROA), regurgitant volume (Rvol). LV ejection fraction (EF %) was calculated by Simpson's method. High sensitive troponin T (hs-TnT), creatine phosphokinase myocardial band (CK-MB) and N-terminal pro-brain natriuretic peptid (NTpro-BNP) levels were compared between two groups. Although PISA-r, EROA and Rvol were similar in both groups at 1st and 3rd days, all were significantly decreased (p = 0.012, p = 0.007, p = 0.011, respectively) and EF was significantly increased (p< 0 .001) in angina (+) group at 3rd month. NTpro-BNP and hs-TnT levels at 1st day and 3rd month were similar, however CK-MB level at 3rd month was found to be significantly lower in the angina (+) group (p = 0.034). At the end of the 3rd month, it was observed that the severity of IMR evaluated by PISA method was decreased and EF increased significantly in patients who defined angina within 72 h prior to STEMI, suggesting a relation with IPC.

Observational study of left ventricular global longitudinal strain in ST-segment elevation myocardial infarction patients with extended pharmaco-invasive strategy: A six months follow-up study

AIMS AND OBJECTIVES

To evaluate left ventricular (LV) function by assessment of LV global longitudinal strain (GLS) in ST-segment elevation myocardial infarction (STEMI) patients who underwent delayed fibrinolysis and coronary intervention (extended pharmaco-invasive strategy), since LV function is one of the determinants of both immediate and long-term outcomes.

METHODS

Prospective study of consecutive STEMI patients who underwent extended pharmaco-invasive strategy. The LV function was estimated using LV GLS at baseline and at 6 months.

RESULTS

The study included eighty-seven STEMI patients who received delayed pharmaco-invasive therapy and coronary intervention. The primary aim of the study was to evaluate a change in LV function by assessment of GLS at 6 months as compared to baseline. Prior to PCI, LV ejection fraction was 48.08 ± 6.23% and GLS was -11.11 ± 2.99%. Procedural success was achieved in all patients. LV ejection fraction after 6 months of follow-up increased to 53.12 ± 5.61% and the GLS improved to -13.03 ± 3.06% In comparison to baseline, there was a significant improvement in both LV ejection fraction and GLS at 6 months of follow-up (P < .001).The cardiac mortality was 1.1% at 6 months.

CONCLUSION

There is a significant improvement of LV function as assessed by GLS and ejection fraction at short-term follow-up. In a stable cohort of STEMI patients, extended pharmaco-invasive strategy is also a reasonable option if PCI cannot be performed within the first 24 hours, due to logistic and infrastructural constraints.

Treatment Windows and Clinical Outcomes in Late-Presenting Patients with ST-Segment Elevation Myocardial Infarction

BACKGROUND

Percutaneous coronary intervention (PCI) is the reperfusion strategy typically used in patients with ST-segment elevation myocardial infarction (STEMI) who present with prolonged ischemic symptoms (>12 hours after onset). However, there is no consensus on an optimal time window for PCI. We examined a real-world cohort, assessing time from symptom onset to balloon inflation in relation to long-term nonfatal recurrent myocardial infarction (MI) or all-cause mortality.

MATERIALS AND METHODS

A total of 825 consecutive patients presenting with ischemic symptoms of STEMI >12 hours after symptom onset and undergoing subsequent primary PCI were grouped by time-to-treatment status (≤7 days or >7 days post-MI). Primary endpoints were nonfatal recurrent MI and all-cause mortality.

RESULTS

Cumulative rates of recurrent nonfatal MI at 2 years were 4.1% and 3.3% in patients with symptom-onset-to-balloon inflation times of ≤7 days and >7 days, respectively (P = 0.049); and corresponding mortality rates were 3.4% and 4.7% (P = 0.238). In Cox multivariate analyses, syndrome-onset-to-balloon-inflation time was not independently predictive of recurrent MI (P = 0.052) or mortality (P = 0.651) at 2 years, once adjusted for certain clinical and angiographic variables known to influence patient outcomes. The 2-year rate of recurrent MI was highest in patients with multivessel coronary artery diseases undergoing primary PCI ≤7 days after symptom onset to balloon inflation (P = 0.005).

CONCLUSIONS

In patients presenting with ischemic signs or symptoms of STEMI >12 hours after initial symptom onset and treated by PCI, symptom-onset-to-balloon-inflation times ≤7 days showed no relation to nonfatal recurrent MI, unless in the presence of multivessel coronary artery diseases.

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.

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.

Thrombus aspiration in late presenters with ST-elevation myocardial infarction: A single-center randomized trial

OBJECTIVES

To examine whether routine thrombus aspiration (TA) is associated with improved myocardial salvage in patients with ST-elevation myocardial infarction (STEMI) presenting ≥12 h after onset of symptoms.

BACKGROUND

TA is a recognized treatment option in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI) especially in the setting of heavy thrombus burden. However, data on the role of TA in STEMI patients presenting late after onset of symptoms are limited.

METHODS

In this single-center prospective randomized study, patients with subacute STEMI presenting ≥12 and ≤48 h after symptom onset were randomized to primary PCI with or without manual TA in a 1:1 ratio. The primary endpoint was the myocardial salvage index assessed with Single Photon Emission Computed Tomography (SPECT) on admission and 4 days later.

RESULTS

A total of 60 patients underwent randomization. Baseline characteristics were comparable between groups. TA was associated with improved myocardial salvage index compared with control group (60.1 ± 11.1% vs 28.1 ± 21.3%; P = <0.001). Furthermore, TA was associated with improved post-procedural TIMI flow (2.9 ± 0.3 vs 2.5 ± 0.6; P = 0.003), myocardial blush grade (2.9 ± 0.3 vs 2.2 ± 0.8, P = <0.001), and reduction in left ventricular end-diastolic dimensions (50.4 ± 4.3 mm vs 54.4 ± 5.8 mm, P = 0.004) compared with the control group. Clinical outcomes at 30 days and 6 months were similar between both groups.

CONCLUSIONS

TA might be associated with improved reperfusion and myocardial salvage especially in STEMI patients presenting after 12 h from symptom onset who are likely to have a heavy thrombus burden.

Relationship Between Prodromal Angina Pectoris and Neutrophil-to Lymphocyte Ratio in Patients With ST Elevation Myocardial Infarction

BACKGROUND

The aim of this study was to investigate the relationship between prodromal angina (PA) with neutrophil-to-lymphocyte ratio (NLR) in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

The study group included 145 patients with STEMI who underwent emergency coronary angiography (CA) within 24hours of symptom onset. Data were collected regarding whether patients had experienced PA before acute myocardial infarction. Seventy-three (73) patients (50.3%) had prodromal angina. Prodromal angina positive and negative groups were compared for demographic characteristics, complete blood count parameters including NLR, blood biochemistry parameters and left ventricular ejection fraction (LVEF).

RESULTS

Neutrophil count, NLR, and troponin I levels were significantly higher in the PA negative group. LVEF after reperfusion and lymphocyte count were lower in the PA negative group. In multivariate regression analysis, NLR (β=-0.419, p<0.001) and LVEF (β=0.418, p<0.001) were found to be significantly associated with the presence of PA in STEMI patients.

CONCLUSIONS

Absence of PA was significantly and independently associated with increased NLR and impaired LVEF after reperfusion, and increased NLR was found as a significant predictor for both lack of PA and impaired LVEF in STEMI patients.

The Slo(w) path to identifying the mitochondrial channels responsible for ischemic protection

Mitochondria play an important role in tissue ischemia and reperfusion (IR) injury, with energetic failure and the opening of the mitochondrial permeability transition pore being the major causes of IR-induced cell death. Thus, mitochondria are an appropriate focus for strategies to protect against IR injury. Two widely studied paradigms of IR protection, particularly in the field of cardiac IR, are ischemic preconditioning (IPC) and volatile anesthetic preconditioning (APC). While the molecular mechanisms recruited by these protective paradigms are not fully elucidated, a commonality is the involvement of mitochondrial K⁺ channel opening. In the case of IPC, research has focused on a mitochondrial ATP-sensitive K⁺ channel (mitoK_ATP), but, despite recent progress, the molecular identity of this channel remains a subject of contention. In the case of APC, early research suggested the existence of a mitochondrial large-conductance K⁺ (BK, big conductance of potassium) channel encoded by the Kcnma1 gene, although more recent work has shown that the channel that underlies APC is in fact encoded by Kcnt2 In this review, we discuss both the pharmacologic and genetic evidence for the existence and identity of mitochondrial K⁺ channels, and the role of these channels both in IR protection and in regulating normal mitochondrial function.

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.

Myocardial Preconditioning: Characteristics, Mechanisms, and Clinical Applications

Perioperative myocardial ischemia and dysfunction re main prevalent after cardiac surgery despite the use of conventional measures to provide myocardial protec tion. Myocardial preconditioning is a powerful, endog enously regulated means of myocardial protection that may also have some clinical usage for patients undergo ing cardiac surgical procedures. The paradoxical con cept of using ischemia as a stimulus for myocardial protection has been studied extensively in animals and humans. The specific characteristics and constituents of preconditioning have been well identified. The mecha nism remains to be completely elucidated due to differ ences among species and experimental models. Some pharmacologic agents are capable of mimicking the classic mechanism of ischemic preconditioning. Pharma cologic and ischemic preconditioning may have signifi cant clinical use and therapeutic efficacy as a means of providing myocardial protection during cardiac surgery, especially in procedures that do not use cardioplegia and cardiopulmonary bypass, such as minimally inva sive coronary artery bypass grafting. This article re views the characteristics, mechanisms, potential clini cal applications, and therapeutic efficacy of myocardial preconditioning.

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.

Remote ischaemic conditioning: cardiac protection from afar

For patients with ischaemic heart disease, remote ischaemic conditioning may offer an innovative, non‐invasive and virtually cost‐free therapy for protecting the myocardium against the detrimental effects of acute ischaemia‐reperfusion injury, preserving cardiac function and improving clinical outcomes. The intriguing phenomenon of remote ischaemic conditioning was first discovered over 20 years ago, when it was shown that the heart could be rendered resistant to acute ischaemia‐reperfusion injury by applying one or more cycles of brief ischaemia and reperfusion to an organ or tissue away from the heart – initially termed ‘cardioprotection at a distance’. Subsequent pre‐clinical and then clinical studies made the important discovery that remote ischaemic conditioning could be elicited non‐invasively, by inducing brief ischaemia and reperfusion to the upper or lower limb using a cuff. The actual mechanism underlying remote ischaemic conditioning cardioprotection remains unclear, although a neuro‐hormonal pathway has been implicated. Since its initial discovery in 1993, the first proof‐of‐concept clinical studies of remote ischaemic conditioning followed in 2006, and now multicentre clinical outcome studies are underway. In this review article, we explore the potential mechanisms underlying this academic curiosity, and assess the success of its application in the clinical setting.

Late percutaneous coronary intervention prevents left ventricular remodeling and improves clinical outcomes in patients with ST-elevation myocardial infarction

BACKGROUND

The optimal strategy for treating late presenters of ST-elevation myocardial infarction (STEMI) remains uncertain.

HYPOTHESIS

percutaneous coronary intervention (PCI) has a favorable effect on left ventricular (LV) remodeling and clinical outcomes in late presenters of STEMI.

METHODS

Patients with STEMI who were hospitalized between 2009 and 2011 at 7 PCI-capable hospitals in China were selected. Cardiac characteristics were reassessed by echocardiography between August 2013 and January 2014. The clinical endpoints were evaluated during a median follow-up period of 36 months.

RESULTS

1090 patients who either underwent late PCI (n = 786) or received standard medical therapy alone (n = 304) was analyzed. Left ventricular remodeling was more pronounced in the conservative-treatment group. Logistic regression revealed that late PCI was independently and negatively correlated with LV remodeling (odds ratio: 0.356, 95% confidence interval [CI]: 0.251-0.505, P < 0.001). Kaplan-Meier analysis showed the lower risks of major adverse cardiovascular events (MACE), all-cause death, and rehospitalization for heart failure in the late-PCI group. Multivariate Cox regression revealed that late PCI was significantly associated with lower risks for MACE, all-cause death, and rehospitalization for heart failure both in all patients (hazard ratio [HR]: 0.507, 95% CI: 0.412-0.625, P < 0.001; HR: 0.419, 95% CI: 0.314-0.559, P < 0.001; and HR: 0.583, 95% CI: 0.379-0.896, P = 0.014, respectively) and in the matched patients (HR: 0.466, 95% CI: 0.358-0.607, P < 0.001; HR: 0.398, 95% CI: 0.277-0.571, P < 0.001; and HR: 0.498, 95% CI: 0.283-0.878, P = 0.016, respectively) by propensity-score analysis.

CONCLUSIONS

Late-PCI strategy prevents LV remodeling and improves clinical outcomes in STEMI patients compared with conservative strategies.

What is Wrong With Cardiac Conditioning? We May be Shooting at Moving Targets

Early recanalization of the occluded culprit coronary artery clearly reduces infarct size in both animal models and patients and improves clinical outcomes. Unfortunately, reperfusion can seldom be accomplished before some myocardium infarcts. As a result there has been an intensive search for interventions that will make the heart resistant to infarction so that reperfusion could salvage more myocardium. A number of interventions have been identified in animal models, foremost being ischemic preconditioning. It protects by activating signaling pathways that prevent lethal permeability transition pores from forming in the heart’s mitochondria at reperfusion. Such conditioning can be accomplished in a clinically relevant manner either by staccato reperfusion (ischemic postconditioning) or by pharmacological activation of the conditioning signaling pathways prior to reperfusion. Unfortunately, clinical trials of ischemic postconditioning and pharmacologic conditioning have been largely disappointing. We suggest that this may be caused by inappropriate use as models intended to mimic the clinical scenario of young healthy animals that receive none of the many drugs currently given to our patients. Patients may be resistant to some forms of conditioning because of comorbidities, for example, diabetes, or they may already be conditioned by adjunct medications, for example, P2Y12 inhibitors or opioids. Incremental technological improvements in patient care may render some approaches to cardioprotection redundant, and thus the clinical target may be continually changing, while our animal models have not kept pace. In remote conditioning, a limb is subjected to ischemia/reperfusion prior to or during coronary reperfusion. Its mechanism is not as well understood as that of ischemic preconditioning, but the results have been very encouraging. In the present article, we will review ischemic, remote, and pharmacologic conditioning and possible confounders that could interfere with their efficacy in clinical trials in 2 settings of myocardial ischemia: (1) primary angioplasty in acute myocardial infarction and (2) elective angioplasty.

Effect of preinfarction angina pectoris on long-term survival in patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention

The influence of preinfarction angina pectoris (AP) on long-term clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) remains controversial. In 5,429 patients with acute myocardial infarction (AMI) enrolled in the Coronary Revascularization Demonstrating Outcome Study in Kyoto AMI Registry, the present study population consisted of 3,476 patients with STEMI who underwent primary PCI within 24 hours of symptom onset and in whom the data on preinfarction AP were available. Preinfarction AP defined as AP occurring within 48 hours of hospital arrival was present in 675 patients (19.4%). Patients with preinfarction AP was younger and more often had anterior AMI and longer total ischemic time, whereas they less often had history of heart failure, atrial fibrillation, and shock presentation. The infarct size estimated by peak creatinine phosphokinase was significantly smaller in patients with than in patients without preinfarction AP (median [interquartile range] 2,141 [965 to 3,867] IU/L vs 2,462 [1,257 to 4,495] IU/L, p <0.001). The cumulative 5-year incidence of death was significantly lower in patients with preinfarction AP (12.4% vs 20.7%, p <0.001) with median follow-up interval of 1,845 days. After adjusting for confounders, preinfarction AP was independently associated with a lower risk for death (hazard ratio 0.69, 95% confidence interval 0.54 to 0.86, p = 0.001). The lower risk for 5-year mortality in patients with preinfarction AP was consistently observed across subgroups stratified by total ischemic time, initial Thrombolysis In Myocardial Infarction flow grade, hemodynamic status, infarct location, and diabetes mellitus. In conclusion, preinfarction AP was independently associated with lower 5-year mortality in patients with STEMI who underwent primary PCI.

Association between clinical presentations before myocardial infarction and coronary mortality: a prospective population-based study using linked electronic records

Background

Ischaemia in different arterial territories before acute myocardial infarction (AMI) may influence post-AMI outcomes. No studies have evaluated prospectively collected information on ischaemia and its effect on short- and long-term coronary mortality. The objective of this study was to compare patients with and without prospectively measured ischaemic presentations before AMI in terms of infarct characteristics and coronary mortality.

Methods and results

As part of the CALIBER programme, we linked data from primary care, hospital admissions, the national acute coronary syndrome registry and cause-specific mortality to identify patients with first AMI (n = 16,439). We analysed time from AMI to coronary mortality (n = 5283 deaths) using Cox regression (median 2.6 years follow-up), comparing patients with and without recent ischaemic presentations. Patients with ischaemic presentations in the 90 days before AMI experienced lower coronary mortality in the first 7 days after AMI compared with those with no prior ischaemic presentations, after adjusting for age, sex, smoking, diabetes, blood pressure and cardiovascular medications [HR: 0.64 (95% CI: 0.57–0.73) P < 0.001], but subsequent mortality was higher [HR: 1.42 (1.13–1.77) P = 0.001]. Patients with ischaemic presentations closer in time to AMI had the lowest seven day mortality (P-trend = 0.001).

Conclusion

In the first large prospective study of ischaemic presentations prior to AMI, we have shown that those occurring closest to AMI are associated with lower short-term coronary mortality following AMI, which could represent a natural ischaemic preconditioning effect, observed in a clinical setting.

Clinical trials registration

Clinicaltrials.gov identifier NCT01604486.

Severity of lethal ischemia/reperfusion injury in rat hearts subjected to ischemic preconditioning is increased under conditions of simulated hyperglycemia

The aim of our study was to characterize resistance to ischemia/reperfusion (I/R) injury in Langendorff-perfused rat hearts and effectivity of ischemic preconditioning (PC) under condition of simulated acute hyperglycemia (SAHG) by perfusion of the hearts with Krebs-Henseleit (KH) solution with elevated glucose concentration (22 mmol/l). I/R injury was induced by 30-min coronary occlusion followed by 120-min reperfusion and PC by two cycles of 5-min occlusion/5-min reperfusion, prior to I/R. The severity of I/R injury was characterized by determination of the size of infarction (IS, expressed in % of area at risk size) and the amount of heart-type fatty acid binding protein (h-FABP, a marker of cell injury) released from the hearts to the effluent. Significantly smaller IS (8.8+/-1 %) and lower total amount of released h-FABP (1808+/-660 pmol) in PC group compared with IS 17.1+/-1.2 % (p<0.01) and amount of h-FABP (8803+/-2415 pmol, p<0.05) in the non-PC control hearts perfused with standard KH solution (glucose 11 mmol/l) confirmed protective effects of PC. In contrast, in SAHG groups, PC enhanced IS (21.4+/-2.2 vs. 14.3+/-1.3 %, p<0.05) and increased total amount of h-FABP (5541+/-229 vs. 3458+/-283 pmol, p<0.05) compared with respective non-PC controls. Results suggest that PC has negative effect on resistance of the hearts to I/R injury under conditions of elevated glucose in vitro.

Preinfarction angina reduces infarct size in ST-elevation myocardial infarction treated with percutaneous coronary intervention

BACKGROUND

Preinfarction angina may act as a clinical surrogate of ischemic preconditioning that may reduce infarct size and improve mortality in the setting of thrombolytic therapy for ST-elevation myocardial infarction. However, the benefits of preinfarction angina in the setting of primary percutaneous coronary intervention with stenting is inconclusive because of the greater achievement of infarct artery patency and speed of reperfusion.

METHODS AND RESULTS

To identify a homogeneous population, we performed a retrospective analysis of 1031 patients admitted with a first ST-elevation myocardial infarction with ischemic times between 1 and 6 hours who received primary percutaneous coronary intervention. We identified 245 patients who had occluded arteries on presentation, of which 79 patients had documented preinfarction angina defined as chest pain within 24 hours of infarction. Infarct size was measured as the peak creatine kinase level, a metric supported in a subgroup by late enhancement on cardiac magnetic resonance imaging. Patients with preinfarction angina (n=79) had a 50% reduction in infarct size compared with those patients without preinfarction angina (n=166) by both peak creatine kinase (1094±75 IU/L versus 2270±102 IU/L; P<0.0001) and creatine kinase area under curve (18 420±18 941 versus 36 810±21 741 IU/h per liter; P<0.0001) despite having identical ischemic times (185±8 minutes versus 181±5 minutes; P=0.67) and angiographic area at risk (24.1±1.2% versus 25.3±0.9%; P=0.43). There was an absolute 4% improvement in left ventricular ejection fraction before discharge in those patients with preinfarction angina (P<0.02).

CONCLUSIONS

The occurrence of preinfarction angina is associated with significant myocardial protection in the setting of primary percutaneous coronary intervention with stenting during ST-elevation myocardial infarction. Because preinfarction angina is relatively common, it is important that these patients be identified in clinical trials investigating therapies designed to reduce reperfusion injury and infarct size.

Pre-infarction angina and outcomes in non-ST-segment elevation myocardial infarction: data from the RICO survey

Background

The presence of pre-infarction angina (PIA) has been shown to confer cardioprotection after ST-segment elevation myocardial infarction (STEMI). However, the clinical impact of PIA in non-ST-segment elevation myocardial infarction (NSTEMI) remains to be determined.

Methods and Results

From the obseRvatoire des Infarctus de Côte d'Or (RICO) survey, 1541 consecutive patients admitted in intensive care unit with a first NSTEMI were included. Patients who experienced chest pain <7 days before the episode leading to admission were defined as having PIA and were compared with patients without PIA. Incidence of in-hospital ventricular arrhythmias (VAs), heart failure and 30-day mortality were collected. Among the 1541 patients included in the study, 693 (45%) patients presented PIA. PIA was associated with a lower creatine kinase peak, as a reflection of infarct size (231(109–520) vs. 322(148–844) IU/L, p<0.001) when compared with the group without PIA. Patients with PIA developed fewer VAs, by 3 fold (1.6% vs. 4.0%, p = 0.008) and heart failure (18.0% vs. 22.4%, p = 0.040) during the hospital stay. Overall, there was a decrease in early CV events by 26% in patients with PIA (19.2% vs. 25.9%, p = 0.002). By multivariate analysis, PIA remained independently associated with less VAs.

Conclusion

From this large contemporary prospective study, our work showed that PIA is very frequent in patients admitted for a first NSTEMI, and is associated with a better prognosis, including reduced infarct size and in hospital VAs. Accordingly, protecting the myocardium by ischemic or pharmacological conditioning not only in STEMI, but in all type of MI merits further attention.

Effects of diabetes on myocardial infarct size and cardioprotection by preconditioning and postconditioning

In spite of the current optimal therapy, the mortality of patients with ischemic heart disease (IHD) remains high, particularly in cases with diabetes mellitus (DM) as a co-morbidity. Myocardial infarct size is a major determinant of prognosis in IHD patients, and development of a novel strategy to limit infarction is of great clinical importance. Ischemic preconditioning (PC), postconditioning (PostC) and their mimetic agents have been shown to reduce infarct size in experiments using healthy animals. However, a variety of pharmacological agents have failed to demonstrate infarct size limitation in clinical trials. One of the possible reasons for the discrepancy between the results of animal experiments and clinical trials is that co-morbidities, including DM, modified myocardial responses to ischemia/reperfusion and to cardioprotective agents. Here we summarize observations of the effects of DM on myocardial infarct size and ischemic PC and PostC and discuss perspectives for protection of DM hearts.

Implications of ST-segment elevation in leads V5 and V6 in patients with reperfused inferior wall acute myocardial infarction

During inferior acute myocardial infarction, ST-segment elevation (ST↑) often occurs in leads V(5) to V(6), but its clinical implications remain unclear. We examined the admission electrocardiograms from 357 patients with a first inferior acute myocardial infarction who had Thrombolysis In Myocardial Infarction 3 flow of the right coronary artery or left circumflex artery within 6 hours after symptom onset. The patients were divided according to the presence (n = 76) or absence (n = 281) of ST↑ >2 mm in leads V(5) and V(6). Patients with ST↑ in leads V(5) and V(6) were subdivided into 2 groups according to the degree of ST↑ in leads III and V(6): ST↑ in lead III greater than in V(6) (n = 53) and ST↑ in lead III equal to or less than in V(6) (n = 23). The perfusion territory of the culprit artery was assessed using the angiographic distribution score, and a mega-artery was defined as a score of ≥0.7. ST↑ in leads V(5) and V(6) with ST↑ in lead III greater than in V(6) and ST↑ in leads V(5) and V(6) with ST↑ in lead III equal to or less than in V(6) were associated with mega-artery occlusion and impaired myocardial reperfusion, as defined by myocardial blush grade 0 to 1. Right coronary artery occlusion was most common (96%) in the former, and left circumflex artery occlusion was most common (96%) in the latter, especially proximal left circumflex occlusion (74%). Multivariate analysis showed that ST↑ in leads V(5) and V(6) with ST↑ in lead III greater than that in V(6) (odds ratio 4.81, p <0.001) and ST↑ in leads V(5) and V(6) with ST↑ in lead III equal or less than that in V(6) (odds ratio 5.96, p <0.001) were independent predictors of impaired myocardial reperfusion. In conclusion, ST↑ in leads V(5) and V(6) suggests a greater risk area and impaired myocardial reperfusion in patients with inferior acute myocardial infarction. Furthermore, comparing the degree of ST↑ in lead V(6) with that in lead III is useful for predicting the culprit artery.

Circadian dependence of infarct size and left ventricular function after ST elevation myocardial infarction

RATIONALE

In rodents, infarct size after ischemia/reperfusion exhibits a circadian dependence on the time of coronary occlusion. It is not known if a similar circadian dependence of infarct size occurs in humans.

OBJECTIVE

To determine if humans exhibit a circadian dependence of infarct size in the setting of ST elevation myocardial infarction (STEMI).

METHODS AND RESULTS

A retrospective analysis of 1031 patients with STEMI referred for primary percutaneous coronary intervention with known ischemic times between 1 and 6 hours identified 165 patients with occluded arteries on presentation without evidence of preinfarction angina or collateral blood flow. Both ischemic duration and angiographic area at risk were not dependent on time of infarct onset. We observed that the extent of infarct size measured by creatine kinase release was significantly associated with time of day onset of infarction (P<0.0001). The greatest myocardial injury occurred at 1:00 am onset of ischemia and 5:00 am onset of reperfusion, with the peak creatine kinase measured at the peak of the curve being 82% higher than that recorded at the trough. Similarly, left ventricular ejection fraction measured within 2 days of infarction was also dependent on time of onset of STEMI with the absolute left ventricular ejection fraction at peak >7% higher than at trough (43% vs 51%; P<0.03). These findings were supported by a subgroup of patients (n = 45) who underwent cardiac MRI measurements of infarct size and area-at-risk measurements.

CONCLUSIONS

The results of this study demonstrate for the first time in humans that myocardial infarct size and left ventricular function after STEMI have a circadian dependence on the time of day onset of ischemia.

Efficacy of cardioprotective 'conditioning' strategies in aging and diabetic cohorts: the co-morbidity conundrum

Evidence obtained in multiple experimental models has revealed that cardiac 'conditioning' strategies--including ischaemic preconditioning, postconditioning, remote conditioning and administration of pharmacological conditioning mimetics--are profoundly protective and significantly attenuate myocardial ischaemia-reperfusion injury. As a result, there is considerable interest in translating these cardioprotective paradigms from the laboratory to patients. However, the majority of studies investigating conditioning-induced cardioprotection have utilized healthy adult animals devoid of the risk factors and co-morbidities associated with cardiovascular disease and acute myocardial infarction. The aim of this article is to summarize the growing consensus that two well established risk factors, aging and diabetes mellitus, may render the heart refractory to the favourable effects of myocardial conditioning, and discuss the clinical implications of a loss in efficacy of cardiac conditioning paradigms in these patient populations.

Beneficial effect of ischemic preconditioning on post-infarction left ventricular remodeling and global left ventricular function

BACKGROUND

Preinfarction angina (PA) is a clinical analogue of ischemic preconditioning that improves postinfarct prognosis. Data concerning the association of PA with post infarction left ventricular (LV) remodeling and LV diastolic function are limited. We aimed to evaluate this association in patients with acute myocardial infarction (AMI) in the modern clinical era of widespread use of revascularization and antiremodeling medical treatment.

METHODS

We studied 53 patients with anterior AMI who underwent complete reperfusion and received up to date antiremodeling medical treatment. LV remodeling, systolic and diastolic function were assessed using 2D echocardiography at baseline and 6 at months follow-up. Patients were divided into two groups regarding the presence or absence of PA.

RESULTS

LV remodeling at follow-up was less frequent in the PA group (25 vs. 55 %, P<.05). Patients with PA had lower end-systolic volume index at baseline and follow up (24.1±6 vs. 30.1±14 ml/m(2), P<.001 and 25.3±8 vs. 35.6±2 ml/m(2), P=.001 respectively). Additionally at 6 months, they had better LV ejection fraction (52.1±9 vs. 42.9±10 %, P=.002) and exhibited improved diastolic filling as reflected by mitral E/e' (14.6±5 vs. 18.8±8, P=.05).

CONCLUSIONS

Ischemic preconditioning in the form of PA promotes better LV systolic and diastolic function in the mid-term and is associated with less postinfarct LV remodeling in this specific study population. The results of the study underline the possible need for further risk stratification of AMI patients regarding the absence of PA.

Preinfarction angina prior to first myocardial infarction does not influence long-term prognosis: a retrospective study with subgroup analysis in elderly and diabetic patients

BACKGROUND AND HYPOTHESIS

Although prodromal angina occurring shortly before an acute myocardial infarction (MI) has protective effects against in-hospital complications, this effect has not been well documented after initial hospitalization, especially in older or diabetic patients. We examined whether angina 1 week before a first MI provides protection in these patients.

METHODS

A total of 290 consecutive patients, 143 elderly (>64 years of age) and 147 adults (<65 years of age), 68 of whom were diabetic (23.4%) and 222 nondiabetic (76.6%), were examined to assess the effect of preceding angina on long-term prognosis (56 months) after initial hospitalization for a first MI.

RESULTS

No significant differences were found in long-term complications after initial hospitalization in these adult and elderly patients according to whether or not they had prodromal angina (44.4% with angina vs 45.4% without in adults; 45.5% vs 58% in elderly, P < 0.2). Nor were differences found according to their diabetic status (61.5% with angina vs 72.7% without in diabetics; 37.3% vs 38.3% in nondiabetics; P = 0.4).

CONCLUSION

The occurrence of angina 1 week before a first MI does not confer long-term protection against cardiovascular complications after initial hospitalization in adult or elderly patients, whether or not they have diabetes.

Chronic nitrate therapy is associated with different presentation and evolution of acute coronary syndromes: insights from 52,693 patients in the Global Registry of Acute Coronary Events

AIMS

Brief episode(s) of ischaemia may increase cardiac tolerance to a subsequent major ischaemic insult ('preconditioning'). Nitrates can pharmacologically mimic ischaemic preconditioning in animals. In this study, we investigated whether antecedent nitrate therapy affords protection toward acute ischaemic events using data from the Global Registry of Acute Coronary Events.

METHODS AND RESULTS

The dataset comprised 52,693 patients from 123 centres in 14 countries: 42,138 (80%) were nitrate-naïve and 10,555 (20%) were on chronic nitrates at admission. In nitrate-naïve patients, admission diagnosis was ST-segment elevation myocardial infarction (STEMI) in 41%, whereas 59% presented with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). In contrast, only 18% nitrate users showed STEMI, whereas 82% presented with NSTE-ACS. Thus, among nitrate users clinical presentation was tilted toward NSTE-ACS by more than four-fold, STEMI occurring in less than one of five patients (P < 0.0001). After adjustment (age, sex, medical history, prior therapy, revascularization, previous angina), chronic nitrate use remained independent predictor of NSTE-ACS (OR 1.36; 95% CI 1.26-1.46; P < 0.0001). Furthermore, regardless of presentation, within both STEMI and NSTEMI populations, antecedent nitrate use was associated with significantly lower levels of CK-MB and troponin (P < 0.0001 for all).

CONCLUSION

In this large multinational registry, chronic nitrate use was associated with a shift away from STEMI in favour of NSTE-ACS and with less release of markers of cardiac necrosis. These findings suggest that in nitrate users acute coronary events may develop to a smaller extent. Randomized, placebo-controlled trials are warranted to establish whether nitrate therapy may pharmacologically precondition the heart toward ischaemic episodes.

Difference of culprit plaque composition between patients with and without pre-infarction angina: an intravascular ultrasound radiofrequency analysis

AIMS

This study was performed to assess the differences in culprit plaque composition between patients with and without pre-infarction angina (PA) by using spectral analysis of intravascular ultrasound (IVUS) radiofrequency (RF) data.

METHODS AND RESULTS

Of 57 patients consecutively admitted to our institution with acute myocardial infarction, pre-intervention IVUS RF data of culprit plaques were obtained and analysed in 35 patients after percutaneous aspiration thrombectomy. Among the 35 patients, 21 patients had PA. Culprit plaques of patients without PA consisted of a higher percentage of the necrotic core component than those with PA (minimum lumen area [MLA]) site, 21.2+/-8.9% versus 9.9+/-9.8%, p=0.0015; entire culprit lesion, 18.9+/-6.3% versus 12.0+/-9.6%, p=0.023). In contrast, culprit plaques of patients with PA contained a higher percentage of the fibrofatty component than those without PA (MLA site, 21.0+/-12.0% versus 11.5+/-7.6%, p=0.013; entire culprit lesion, 16.8+/-7.9% versus 12.1+/-5.5%, p=0.062). There was no significant difference in quantitative parameters between the patients with and without PA.

CONCLUSIONS

Culprit plaques of patients with PA were different from those without PA. Plaque composition may play an important role in the occurrence of PA.

Combined prognostic utility of white blood cell count, plasma glucose, and glomerular filtration rate in patients undergoing primary stent placement for acute myocardial infarction

Although high white blood cell (WBC) count and plasma glucose (PG) and low glomerular filtration rate (GFR) on admission have been associated with poor outcomes after acute myocardial infarction (AMI), the combined prognostic utility of these 3 variables was unclear. The association of WBC count, PG, and GFR on admission to in-hospital outcomes was examined in 2,633 patients who underwent primary stent placement for ST-segment elevation AMI within 48 hours after symptom onset. In-hospital mortality progressively increased as the number of the variables of high WBC count (> or =11,120/microl; upper tertile), high PG (> or =10.4 mmol/L; upper tertile), and low GFR (< or =60 ml/min/1.73 m(2); lower tertile) increased. Patients with all 3 variables had a strikingly higher in-hospital mortality rate (25.9%). After adjusting for baseline characteristics, multivariate analysis showed that compared with patients who had none of these variables, odds ratios for in-hospital mortality were 1.63 (95% confidence interval [CI] 0.88 to 3.03, p = 0.12) in patients with only 1 variable, 2.33 (95% CI 1.28 to 3.96, p = 0.047) in those with 2 variables, and 6.16 (95% CI 2.98 to 12.6, p <0.001) in those with all 3 variables. In conclusion, combined evaluation of WBC count, PG, and GFR on admission was a simple and useful method for the early prediction of risk of in-hospital death in patients undergoing primary stent placement for ST-segment elevation AMI.

The impact of preinfarction angina on electrocardiographic ischemia grades in patients with acute myocardial infarction treated with primary percutaneous coronary intervention

OBJECTIVE

Grade 3 ischemia (G3I) is defined as ST elevation with distortion of the terminal portion of the QRS (emergence of the J point > 50% of the R wave in leads with qR configuration, or disappearance of the S wave in leads with an Rs configuration). Patients with G3I on the presenting electrocardiogram (ECG) had worse prognosis than the patients with lesser (grade 2-G2I) ischemia. The aim of this study is to examine the effects of preinfarct angina (PIA) on electrocardiographic ischemia grades.

METHODS

One hundred forty-eight consecutive patients with ST-segment myocardial infarction (STEMI) were included in this study. All patients underwent primary percutaneous coronary intervention. The admission ECGs was analyzed retrospectively for electrocardiographic ischemia grades and compared with the presence of PIA.

RESULTS

Study population consisted of 110 patients with G2I (88 men, mean age = 63 +/- 6 years) and 38 patients with G3I (32 men, mean age = 61 +/- 8 years). Baseline characteristics of the groups were the same except for patients with G3I had significantly longer pain to balloon time and higher admission creatine kinase MB isoenzyme (CK-MB) levels. Tissue myocardial perfusion grade (TMPG) was better in patients with G2I. While 18 patients (47%) with G3I had PIA, 81 patients (70%) with G2I had PIA (P = 0.005). Although pain to balloon time and admission CK-MB were independent predictor of worse electrocardiographic ischemia grade (OR 1.69, 95% CI 1.09-2.62; P = 0.01; OR 1.01, 1.00-1.02, P = 0.04), PIA and left ventricular ejection time (LVEF) were independent predictors of better electrocardiographic ischemia grade (OR 0.4, 95% CI 0.17-0.90; P = 0.02, OR 0.92, 95% CI 0.85-0.99; P = 0.03, respectively) in multivariate logistic regression analysis.

CONCLUSION

PIA is one of the most important clinical predictors of better ischemia grades especially when combined with the pain to balloon time, LVEF, and admission CK-MB levels in patients with STEMI. This study provided another evidence for the protective effects of PIA.