Sustained Benefit 20 Years After Reperfusion Therapy in Acute Myocardial Infarction

Temporal Change in the Remaining Life Expectancy in People Who Underwent Percutaneous Coronary Intervention

Whether percutaneous coronary intervention (PCI) is effective in improving long-term survival in an Australian PCI cohort remains unclear. We aimed to examine the change in the remaining life expectancy for patients who underwent PCI over the past decade. Patient data from the Melbourne Interventional Group were divided into four 3-year periods (2005 to 2007, 2008 to 2010, 2011 to 2013, and 2014 to 2016) for survival analysis. The primary outcome was time to death after PCI. Kaplan-Meier survival curves for overall survival were constructed to estimate the 5-year survival. To extrapolate the overall survival curve to the lifetime time horizon, 6 parametric survival distributions were fitted to the individual patient-level data against the Kaplan-Meier curve. The best fit distribution was selected based on goodness-of-fit statistics and expert opinion. The combination of annual mortality post-PCI from the parametric survival analysis and the background mortality by age informed the overall mortality rate. The life expectancy was compared with the general Australians. In addition, the utility weight of post-PCI patients was used to estimate the quality-adjusted life years gained. A total of 27,301 patients with a mean age of 64.4 ± 12 years were included. The base-case results showed that over the 4 time periods, the remaining life expectancy for patients aged 64.4 years on average at the time of PCI remained relatively stable except for period 4: 18.12 years (2005 to 2007), 17.56 years (2008 to 2010), 18.39 years (2011 to 2013), and 17.25 years (2014 to 2016), respectively. The quality-adjusted life years gained showed a similar trend: 14.86 (2005 to 2007), 14.40 (2008 to 2010), 15.07 (2011 to 2013), and 14.13 (2014 to 2016) separately. In conclusion, the widened gap in life expectancy in post-PCI patients versus the general Australian over the 2014 to 2016 period suggests the need for improved implementation of prevention strategies for coronary heart disease. Enhanced disease management after PCI that lowers residual mortality risk is recommended to extend the survival of patients with coronary heart disease.

A Review of Prognosis Model Associated With Cardiogenic Shock After Acute Myocardial Infarction

Objective: Cardiogenic shock seriously affects the survival rate of patients. However, few prognostic models are concerned with the score of cardiogenic shock, and few clinical studies have validated it. In order to optimize the diagnosis and treatment of myocardial infarction complicated with cardiogenic shock and facilitate the classification of clinical trials, the prognosis score model is urgently needed. Methods: Cardiogenic shock, severe case, prognosis score, myocardial infarction and external verification were used as the search terms to search PubMed, Embase, Web of Science, Cochrane, EBSCO (Medline), Scopus, BMC, NCBI, Oxford Academy, Science Direct, and other databases for pertinent studies published up until 1 August 2021. There are no restrictions on publication status and start date. Filter headlines and abstracts to find articles that may be relevant. The list of references for major studies was reviewed to obtain more references. Results and Conclusions: The existing related models are in urgent need of more external clinical verifications. In the meanwhile, with the development of molecular omics and the clinical need for optimal treatment of CS, it is urgent to establish a prognosis model with higher differentiation and coincidence rates.

10-Year Follow-Up After Revascularization in Elderly Patients With Complex Coronary Artery Disease

BACKGROUND

The optimal revascularization strategy for the elderly with complex coronary artery disease remains unclear.

OBJECTIVES

The goal of this study was to investigate 10-year all-cause mortality, life expectancy, 5-year major adverse cardiac or cerebrovascular events (MACCE), and 5-year quality of life (QOL) after percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) in elderly individuals (>70 years old) with 3-vessel disease (3VD) and/or left main disease (LMD).

METHODS

In the present pre-specified analysis on age of the SYNTAX Extended Survival study, 10-year all-cause death and 5-year MACCE were compared with Kaplan-Meier estimates and Cox proportional hazards models among elderly or nonelderly patients. Life expectancy was estimated by restricted mean survival time within 10 years, and QOL status according to the Seattle Angina Questionnaire up to 5 years was assessed by linear mixed-effects models.

RESULTS

Among 1,800 randomized patients, 575 patients (31.9%) were elderly. Ten-year mortality did not differ significantly between PCI and CABG in elderly (44.1% vs. 41.1%; hazard ratio [HR]: 1.08; 95% confidence interval [CI]: 0.84 to 1.40) and nonelderly patients (21.1% vs. 16.6%; HR: 1.30; 95% CI: 1.00 to 1.69; p_interaction = 0.332). Among elderly patients, 5-year MACCE was comparable between PCI and CABG (39.4% vs. 35.1%; HR: 1.18; 95% CI: 0.90 to 1.56), whereas it was significantly higher in PCI over CABG among nonelderly patients (36.3% vs. 23.0%; HR: 1.69; 95% CI: 1.36 to 2.10; p_interaction = 0.043). There were no significant difference in life expectancy (mean difference: 0.2 years in favor of CABG; 95% CI: -0.4 to 0.7) and 5-year QOL status between PCI and CABG among elderly patients.

CONCLUSIONS

Elderly patients with 3VD and/or LMD had comparable 10-year all-cause death, life expectancy, 5-year MACCE, and 5-year QOL status irrespective of revascularization mode. (Synergy Between PCI With TAXUS and Cardiac Surgery: SYNTAX Extended Survival [SYNTAXES]; NCT03417050) (SYNTAX Study: TAXUS Drug-Eluting Stent Versus Coronary Artery Bypass Surgery for the Treatment of Narrowed Arteries [SYNTAX]; NCT00114972).

Analysis of the COMPARE-AMI trial: First report of long-term safety of CD133+ cells

BACKGROUND

Data related to long-term safety of intracoronary (IC) injection of CD133+ bone marrow stem cells (BMSC) following an acute myocardial infarction (MI) are still lacking.

METHODS

COMPARE-AMI is a double-blind, placebo-controlled phase II clinical trial evaluating the safety and efficacy of IC injection of CD133+ enriched hematopoietic BMSC in patients with ST-elevation myocardial infarction (STEMI) and persistent left ventricular (LV) dysfunction following successful primary percutaneous coronary intervention (PCI). Herein, we report outcomes up to ten years of follow-up.

RESULTS

Between November 2007 and July 2012, we enrolled 38 patients in our study. Males were 89% and the median age was 50.5 years. Baseline left ventricular ejection fraction (LVEF) was 40.0%, and 90% of lesions were located in the left anterior descending (LAD) artery. The median follow-up time was 8.5 years IQR [7.9, 10.0]. Using Kaplan-Meier methods, MACE-free survival up to 10 years was 77.3% overall. IC injection of CD133+ BMSC was associated with a similar event-free survival rate compared to placebo (87.8% vs. 66.3%, p = .37). Two cancer cases in each group were recorded. No malignant arrhythmias were observed.

CONCLUSIONS

IC injection of CD133+ BMSC is safe up to 10 years of follow-up. The long-term efficacy needs to be confirmed by a larger randomized trial.

Association of Guideline-Based Admission Treatments and Life Expectancy After Myocardial Infarction in Elderly Medicare Beneficiaries

BACKGROUND

Guideline-based admission therapies for acute myocardial infarction (AMI) significantly improve 30-day survival, but little is known about their association with long-term outcomes.

OBJECTIVES

This study evaluated the association of 5 AMI admission therapies (aspirin, beta-blockers, acute reperfusion therapy, door-to-balloon [D2B] time ≤90 min, and time to fibrinolysis ≤30 min) with life expectancy and years of life saved after AMI.

METHODS

We analyzed data from the Cooperative Cardiovascular Project, a study of Medicare beneficiaries hospitalized for AMI, with 17 years of follow-up. Life expectancy and years of life saved after AMI were calculated using Cox proportional hazards regression with extrapolation using exponential models.

RESULTS

Survival for recipients and non-recipients of the 5 guideline-based therapies diverged early after admission and continued to diverge during 17-year follow-up. Receipt of aspirin, beta-blockers, and acute reperfusion therapy on admission was associated with longer life expectancy of 0.78 (standard error [SE]: 0.05), 0.55 (SE: 0.06), and 1.03 (SE: 0.12) years, respectively. Patients receiving primary percutaneous coronary intervention (PCI) within 90 min lived 1.08 (SE: 0.49) years longer than patients with D2B times >90 min, and door-to-needle (D2N) times ≤30 min were associated with 0.55 (SE: 0.12) more years of life. A dose-response relationship was observed between longer D2B and D2N times and shorter life expectancy after AMI.

CONCLUSIONS

Guideline-based therapy for AMI admission is associated with both early and late survival benefits, and results in meaningful gains in life expectancy and large numbers of years of life saved in elderly patients.

Report of the European Society of Cardiology Cardiovascular Round Table regulatory workshop update of the evaluation of new agents for the treatment of acute coronary syndrome: Executive summary

Regulatory authorities interpret the results of randomized controlled trials according to published principles. The European Medicines Agency (EMA) is planning a revision of the 2000 and 2003 guidance documents on clinical investigation of new medicinal products for the treatment of acute coronary syndrome (ACS) to achieve consistency with current knowledge in the field. This manuscript summarizes the key output from a collaborative workshop, organized by the Cardiovascular Round Table and the European Affairs Committee of the European Society of Cardiology, involving clinicians, academic researchers, trialists, European and US regulators, and pharmaceutical industry researchers. Specific questions in four key areas were selected as priorities for changes in regulatory guidance: patient selection, endpoints, methodologic issues and issues related to the research for novel agents. Patients with ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) should be studied separately for therapies aimed at the specific pathophysiology of either condition, particularly for treatment of the acute phase, but can be studied together for other treatments, especially long-term therapy. Unstable angina patients should be excluded from acute phase ACS trials. In general, cardiovascular death and reinfarction are recommended for primary efficacy endpoints; other endpoints may be considered if specifically relevant for the therapy under study. New agents or interventions should be tested against a background of evidence-based therapy with expanded follow-up for safety assessment. In conclusion, new guidance documents for randomized controlled trials in ACS should consider changes regarding patient and endpoint selection and definitions, and trial designs. Specific requirements for the evaluation of novel pharmacological therapies need further clarification.

Remote Ischemic Postconditioning Ameliorates the Mesenchymal Stem Cells Engraftment in Reperfused Myocardium

Objectives

Remote Ischemic postconditioning (RIPoC) is a cardioprotective strategy for alleviating the reperfusion injury. We hypothesized that RIPoC or ischemic postconditioning (IPoC) could protect the engrafted mesenchymal stem cells (MSCs) in reperfusion myocardium.

Methods

Female Sprague-Dawley rats were subject to 30 minutes of occlusion of left anterior descending (LAD). Ischemia reperfusion (IR) received reperfusion without interruption after ischemia. RIPoC received 3 cycles of 30 seconds reperfusion and re-occlusion on the limb at the onset of reperfusion. IPoC received 3 cycles of 30 seconds reperfusion and re-occlusion on the LAD at the same time. Male MSCs were intramyocardially administered after ischemia.

Results

Compared with that in IR group, ischemic myocardium in RIPoC+IPoC group, RIPoC group and IPoC group were found to have higher anti-oxidative stress and mitochondrial function level, lower lipid peroxidation and inflammational injury level, higher level of stromal cell derived factor-1 alpha and vascular endothelium growth factor gene expression at 3 days later. By immunohistochemical examination and quantitative polymerase chain reaction, more engrafted MSCs, better cardiac function and less cardiac fibrosis in RIPoC+IPoC group, RIPoC group and IPoC group were detected at 3 weeks after delivery. There were no significant differences between RIPoC and RIPoC+IPoC group.

Conclusions

Combination therapy using intramyocardial MSCs transplantation with RIPoC enhanced transplantation efficiency and cardiac function, and reduced cardiac fibrosis. These beneficial effects were mainly attributed to hospitable milieu for engrafted cells. IPoC could not render additional effect on MSCs engraftment elicited by RIPoC.

Mechanical post-conditioning in STEMI patients undergoing primary percutaneous coronary intervention

Although early myocardial reperfusion via primary percutaneous coronary intervention (PCI) allows the preservation of left ventricular function and improves outcome, the acute restoration of blood flow may contribute to the pathophysiology of infarction, a complex phenomenon called reperfusion injury. First described in animal models of coronary obstruction, mechanical post-conditioning, a sequence of repetitive interruption of coronary blood flow applied immediately after reopening of the occluded vessel, was able to reduce the infarct size. However, evidence of its real benefit remains controversial. This review describes the mechanisms of post-conditioning action and the different protocols employed focusing on its impact on primary PCI outcome.

Long-term survival benefits of thrombolysis: the Royal College of General Practitioners' myocardial infarction study

OBJECTIVE

To investigate whether there is a long-term survival benefit from receipt of thrombolysis in routine care particularly pre-hospital thrombolysis, using 20 year mortality data from the RCGP myocardial infarction (MI) cohort study.

METHODS

During 1991-92 the RCGP MI study assessed GP delivery of thrombolysis. Participants who received pre-hospital thrombolysis (n = 290), thrombolysis in hospital (n = 781) or no thrombolysis (n = 2021) were followed and mortality data collected to June 2012. The relationship between thrombolysis and survival time was analysed using Cox regression at 28 days, 1, 5, 10, 15 years post-AMI, and at end of follow-up (~20 years post-AMI).

RESULTS

Compared to those who did not receive it, participants who received thrombolysis had a significant survival benefit at 28 days [adjusted hazard ratio (HR) 0.72, 95% confidence interval (CI): 0.58-0.90]; 1 year (adjusted HR 0.69, 95% CI: 0.57-0.83); 5 years (adjusted HR 0.76, 95% CI: 0.66-0.86); 10 years (adjusted HR 0.85, 95% CI: 0.77-0.95) and 15 years (adjusted HR 0.88, 95% CI: 0.80-0.96) post-AMI until end of follow-up (adjusted HR 0.92, 95% CI: 0.84-1.00). Pre versus in-hospital thrombolysis did not appear beneficial, although there was evidence among the pre-hospital group that short symptom onset-to-needle times conferred greater benefit.

CONCLUSIONS

We found substantial long-term survival benefits associated with thrombolysis when used in routine care. Although primary percutaneous coronary intervention (pPCI) is now the choice treatment, thrombolysis remains an important option when pPCI cannot be delivered within 120 minutes of diagnosis.

Life-years gained by smoking cessation after percutaneous coronary intervention

Previous studies have shown that smoking cessation after a cardiac event reduces the risk of subsequent mortality in patients. The aim of this study was to describe the effect of smoking cessation in terms of prolonged life-years gained. The study sample comprised 856 patients who underwent percutaneous coronary intervention (PCI; balloon angioplasty) during 1980 to 1985. Patients were followed up for 30 years and smoking status at 1 year could be retrieved in 806 patients. The 27 patients who died within 1 year were excluded from the analysis. The median follow-up was 19.5 years (interquartile range 6.0 to 23.0). Cumulative 30-year survival rate was 29% in the group of patients who quit smoking and 14% in persistent smokers (p = 0.005). After adjustment for baseline characteristics at the time of PCI, smoking cessation remained an independent predictor of lesser mortality (adjusted hazard ratio 0.57, 95% confidence interval 0.46 to 0.71). The estimated life expectancy was 18.5 years in those who quit smoking and 16.4 years in the persistent smokers (p <0.0001). In conclusion, in patients with coronary heart disease who underwent PCI in the late 1980s, smoking cessation resulted in at least 2.1 life-years gained.

The Seattle Post Myocardial Infarction Model (SPIM): prediction of mortality after acute myocardial infarction with left ventricular dysfunction

AIMS

Ischemic heart disease is a leading worldwide cause of death. The Seattle Post Myocardial Infarction Model (SPIM) was developed to predict survival 6 months to 2 years after an acute myocardial infarction with evidence of left ventricular dysfunction.

METHODS AND RESULTS

A total of 6632 subjects from the EPHESUS trial were used to derive the predictive model, while 5477 subjects from the OPTIMAAL trial were used to validate the model. Cox proportional hazards modeling was used to develop a multivariate risk score predictive of all-cause mortality. The SPIM risk score integrated lab and vital parameters, Killip class, reperfusion or revascularization, the number of cardiac evidence-based medicines (aspirin, statin, β blocker, ACEI/ARB, aldosterone blocker), and the number of cardiac risk factors. The model was predictive of all-cause mortality after myocardial infarction, with an AUC of 0.75 at 6 months and 0.75 at 2 years in the derivation cohort and 0.77 and 0.78 for the same time points in the validation cohort. Model predicted versus Kaplan-Meier observed survival was excellent in the derivation cohort. It remained so in the validation cohort--84.9% versus 85.0% at 2 years. The 10% of subjects with the highest predicted risk had approximately 25 times higher mortality at 2 years than the 10% of subjects with the lowest predicted risk.

CONCLUSION

The SPIM score was a powerful predictor of outcomes after myocardial infarction with left ventricular dysfunction. Its highly accurate predictions should improve patient and physician understanding of survival and may prove a useful tool in post-infarct risk stratification.

Myocardial infarction and stem cells

Permanent loss of cardiomyocytes and scar tissue formation after myocardial infarction (MI) results in an irreversible damage to the cardiac function. Cardiac repair (replacement, restoration, and regeneration) is, therefore, essential to restore function of the heart following MI. Existing therapies lower early mortality rates, prevent additional damage to the heart muscle, and reduce the risk of further heart attacks. However, there is need for treatment to improve the infarcted area by replacing the damaged cells after MI. Thus, the cardiac tissue regeneration with the application of stem cells may be an effective therapeutic option. Recently, interest is more inclined toward myocardial regeneration with the application of stem cells. However, the potential benefits and the ability to improve cardiac function with the stem cell-based therapy need to be further addressed. In this review, we focus on the clinical applications of stem cells in the cardiac repair.

Encouraging survival rates in patients with acute myocardial infarction treated with an intra-aortic balloon pump

OBJECTIVE: To evaluate a 30-day and long-term outcome of patients with acute myocardial infarction (AMI) treated with intra-aortic balloon pump (IABP) counterpulsation and to identify predictors of a 30-day and long-term all-cause mortality. METHODS: Retrospective cohort study of 437 consecutive AMI patients treated with IABP between January 1990 and June 2004. A Cox proportional hazards model was used to identify predictors of a 30-day and long-term all-cause mortality. RESULTS: Mean age of the study population was 61 ± 11 years, 80% of the patients were male, and 68% had cardiogenic shock. Survival until IABP removal after successful haemodynamic stabilisation was 78% (n = 341). Cumulative 30-day survival was 68%. Median follow-up was 2.9 years (range, 6 months to 15 years). In patients who survived until IABP removal, cumulative 1-, 5-, and 10-year survival was 75%, 61%, and 39%, respectively. Independent predictors of higher long-term mortality were prior cerebrovascular accident (hazard ratio (HR), 1.8; 95% confidence interval (CI), 1.0-3.4), need for antiarrhythmic drugs (HR, 2.3; 95% CI, 1.5-3.3), and need for renal replacement therapy (HR, 2.3; 95% CI, 1.2-4.3). Independent predictors of lower long-term mortality were primary percutaneous coronary intervention (PCI; HR, 0.6; 95% CI, 0.4-1.0), failed thrombolysis with rescue PCI (HR, 0.5; 95% CI, 0.3-0.9), and coronary artery bypass grafting (HR, 0.3; 95% CI, 0.1-0.5). CONCLUSIONS: Despite high in-hospital mortality in patients with AMI treated with IABP, a favourable number of patients survived in the long-term. These results underscore the value of aggressive haemodynamic support of patients throughout the acute phase of AMI.

Contribution of delayed intracellular pH recovery to ischemic postconditioning protection

Ischemic postconditioning (PoCo) has been proven to be a feasible approach to attenuate reperfusion injury and enhance myocardial salvage in patients with acute myocardial infarction, but its mechanisms have not been completely elucidated yet. Recent studies demonstrate that PoCo may delay the recovery of intracellular pH during initial reperfusion, and that its ability to limit infarct size critically depends on this effect. Prolongation of postischemic intracellular acidosis inhibits hypercontracture, mitochondrial permeability transition, calpain-mediated proteolysis, and gap junction-mediated spread of injury during the first minutes of reflow. This role of prolonged acidosis does not exclude the participation of other pathways in PoCo-induced cardioprotection. On the contrary, it may allow these pathways to act by preventing immediate reperfusion-induced cell death. Moreover, the existence of interactions between intracellular acidosis and endogenous protection signaling cannot be excluded and needs to be investigated. The role of prolonged acidosis in PoCo cardioprotection has important implications in the design of optimal PoCo protocols and in the translation of cardioprotective strategies to patients with on-going myocardial infarction receiving coronary reperfusion.

Toll-like receptor 2 signaling triggers fatal arrhythmias upon myocardial ischemia-reperfusion

OBJECTIVE

Restoration of myocardial blood flow after ischemia triggers an inflammatory response involving toll-like receptors. Toll-like receptor 2 deficiency is associated with a reduced infarct size after myocardial ischemia and reperfusion. Because a marked mortality was observed in C3HeN wild-type mice, which was absent in TLR2 mice, we tested whether cardiac arrhythmias are the underlying pathology and aimed to elucidate how toll-like receptor 2 ligation might prevent lethal arrhythmias.

DESIGN

Experimental animal model.

SETTING

University hospital research laboratory.

SUBJECTS

Male C3HeN mice.

INTERVENTIONS

Myocardial ischemia and reperfusion was surgically induced by ligation of the left anterior descending coronary artery for 20 mins followed by 24 hrs of reperfusion. Electrocardiography was continuously recorded during the observation period through an implantable telemetry transmitter to detect cardiac arrhythmias during reperfusion.

MEASUREMENTS AND MAIN RESULTS

Toll-like receptor 2 expression was associated with a 51% mortality rate (23 of 45 mice died) after myocardial ischemia and reperfusion. Absence of toll-like receptor 2 improved survival toward 100% (17 of 17 mice survived). Electrocardiography diagnostics in conscious animals and histologic analysis revealed that absence of toll-like receptor 2 signaling prevented the formation of pathologic heart rate turbulence after myocardial ischemia and reperfusion and modulated the density of connexin 43-positive gap junctions in the ischemic area compared with wild-type hearts, indicating arrhythmia as the cause underlying the observed mortality.

CONCLUSIONS

The results presented here indicate toll-like receptor 2 as a novel target for the prevention of lethal arrhythmic complications after myocardial ischemia and reperfusion.

Trends in mortality of acute myocardial infarction after discharge from the hospital

BACKGROUND

We assessed trends in the prognosis of patients with acute myocardial infarction hospitalized in New Jersey hospitals. In recent decades, in-hospital mortality has declined markedly but the decline in longer-term mortality is less pronounced, implying that mortality after discharge has worsened.

METHODS AND RESULTS

Using the Myocardial Infarction Data Acquisition System (MIDAS), we examined the outcomes of 285 397 patients hospitalized for a first acute myocardial infarction between 1986 and 2007. Mortality at discharge decreased by 9.4% from 16.9% to 7.5% (annual change, -0.44; 95% confidence interval, -0.49 to -0.40), but the decrease at 1 year was less pronounced (6.4%) because of an increase in mortality from discharge to 1 year after discharge (from 12.1% to 13.9%; annual change, +0.15; 95% confidence interval, +0.10 to +0.20). Mortality from 30 days after discharge to 1 year, a measure not affected by length of stay, increased by 1.2% (annual change, +0.10; 95% confidence interval, +0.06 to +0.23). The effect was more evident in the older age groups and was due to noncardiovascular mortality, especially from respiratory and renal diseases, septicemia, and cancer. All effects remained statistically significant (P<0.0001) after adjustment for demographics, comorbidities, infarction type, complications, and interventions. Piecewise linear regressions confirmed these trends.

CONCLUSIONS

Postdischarge mortality of patients with acute myocardial infarction is increasing, primarily because of higher noncardiovascular mortality in the older age groups.

Funding opportunities for investigators in the early stages of career development

Many sources of advice and guidance are available to the early career investigator. Generally, mentors serve as the primary source of information, although program and review officers are the most underutilized resources. This article organizes these opportunities to enable early career investigators to plot a rational trajectory for career success. A list of the major agencies that provide grant support for early career investigators is included. In addition, funding opportunities are organized on the basis of the stage in career development pathway and the type of terminal degree.

Universal reperfusion therapy can be implemented: lessons from 20 years of management of patients admitted within 6 hours of symptom onset with ST-segment elevation acute myocardial infarction

AIM

To describe longitudinal trends in patients' characteristics, management and hospital outcomes over 20 years of therapy for ST-segment elevation myocardial infarction (STEMI).

METHODS

From 1988 to 2007, 2100 consecutive patients with STEMI were admitted within 6 hours of symptom onset to a centre with a systematic reperfusion policy. The population was divided into three periods 1988-1996, 1996-2001 and 2001-2007.

RESULTS

The baseline risk of mortality increased over time (p=0.02). Use of primary PCI increased and the proportion not receiving reperfusion therapy decreased (from 11.4 to 4.2%, p=0.0001). Adjunctive use of stents and glycoprotein IIb/IIIa antagonists increased. The proportion of patients achieving acute TIMI-3 flow in the infarct artery increased (81 to 92%, p=0.001), while time from symptom onset to reperfusion decreased (240 to 205 min, p<0.0001). This was associated with a decrease in age- and sex-adjusted in-hospital mortality from 8.9 to 7.7% and eventually 5.4% (p<0.01). However, the mortality of patients with cardiogenic shock was unaffected (76, 62 and 61%, respectively, p=0.18).

CONCLUSION

Reperfusion therapy can be implemented in up to 96% of STEMI patients admitted within 6 hours of symptom onset and this is associated with improvements in outcomes. Further improvements are needed in the management of patients with cardiogenic shock.

Post-conditioning restores pre-ischaemic receptor coupling in rat isolated hearts

BACKGROUND AND PURPOSE

Ischaemic preconditioning (IPC) and ischaemic post-conditioning (IPoC) activate signal transduction pathways that are also involved in receptor de- and re-sensitization such as phosphatidylinositol (PI) 3-kinase. Therefore, IPC and IPoC may affect post-infarct receptor coupling.

EXPERIMENTAL APPROACH

Rat isolated hearts (Langendorff mode, constant flow) were exposed to 45 min flow arrest followed by 120 min reperfusion, including IPC or IPoC. Control hearts were perfused without a 45 min flow arrest. Left ventricular developed pressure (LVdevP) was determined. Thirty min after reperfusion, hearts were exposed to parathyroid hormone-related peptide (PTHrP) or isoprenaline for 10 min to monitor receptor responsiveness. Reperfusion injury was quantified by enzyme release.

KEY RESULTS

IPC and IPoC significantly reduced enzyme release compared with ischaemia and reperfusion alone by 75% and 62% respectively. Wortmannin or chelerythrine inhibiting either PI 3-kinase or protein kinase C, respectively, attenuated protection. Application of PTHrP 30 min after reperfusion did not change LVdevP in hearts exposed to ischaemia (+1 +/- 11%), but IPoC restored the normal and non-ischaemic response to PTHrP characterized by a negative inotropism (-8.3 +/- 3.9% and -12.9 +/- 6.1%). IPC restored a small negative inotropic effect (-4.4 +/- 4.7%). Application of a PTHrP receptor antagonist during the 45 min flow arrest attenuated receptor desensitization (DeltaLVdevP: -6.1 +/- 1.7%). Wortmannin but not chelerythrine attenuated the re-sensitizing effect of IPoC on post-ischaemic receptor coupling (DeltaLVdevP: +6.2 +/- 10.5 and -15.0 +/- 7.7%). As observed with PTHrP receptors, IPoC restored beta-adrenoceptors (DeltaLVdevP: +9.3 +/- 11.8% vs. 62.3 +/- 15.8%).

CONCLUSIONS AND IMPLICATIONS

IPoC restores PTHrP receptor coupling in a PI 3-kinase-dependent way. A similar mechanism may allow beta-adrenoceptor re-sensitization.

Three life-years gained from smoking cessation after coronary artery bypass surgery: a 30-year follow-up study

BACKGROUND

Previous studies have shown that smoking cessation after a cardiac event reduces the risk of subsequent mortality in patients, but the effect of smoking cessation in terms of prolonged life-years is not yet known.

METHODS

We analyzed the 30-year clinical outcome of the first 1,041 consecutive patients (age at operation 51 years, 92% male) who successfully underwent isolated venous coronary artery bypass surgery between 1971 and 1980. All 551 smokers (53%) were included in this study. Of these, 43% stopped smoking throughout the first year whereas 57% persisted smoking.

RESULTS

The median follow-up was 29 years (range 26-36 years). The cumulative 10-, 20-, and 30-year survival rates were 88%, 49%, and 19%, respectively, in the group of patients who quit smoking, and only 77%, 36%, and 11%, respectively, in the persistent smokers (P < .0001). After adjusting for all baseline characteristics, smoking cessation remained an independent predictor of lower mortality (hazard ratio 0.60, 95% CI 0.48-0.72). We were able to assess the exact life expectancy by calculating the area under the Kaplan-Meier curves. Life expectancy in the quitters was 20.0 years and 17.0 years in the persistent smokers (P < .0001).

CONCLUSIONS

Using 30-year follow-up data, we estimated that self-reported smoking cessation after coronary artery bypass surgery was associated with a life expectancy gain of 3 years. Smoking cessation turned out to have a greater effect on reducing the risk of mortality than the effect of any other intervention or treatment.

A role for the RISK pathway and K(ATP) channels in pre- and post-conditioning induced by levosimendan in the isolated guinea pig heart

BACKGROUND AND PURPOSE

Myocardial reperfusion injury prevents optimal salvage of the ischaemic myocardium, and adjunct therapy that would significantly reduce reperfusion injury is still lacking. We investigated whether (1) the heart could be pre- and/or post-conditioned using levosimendan (levosimendan pre-conditioning (LPC) and levosimendan post-conditioning (LPostC)) and (2) the prosurvival kinases and/or the sarcolemmal or mitochondrial K(ATP) channels are involved.

EXPERIMENTAL APPROACH

Isolated guinea pig hearts were treated with two 5 min cycles of levosimendan (0.1 microM) interspersed with vehicle perfusion, or two 5 min cycles of ischaemia/reperfusion, before coronary artery ligation (CAL) for 40 min at 36.5 degrees C. Hearts were treated with mitochondrial or sarcolemmal K(ATP) channel blockers before LPC or LPostC. For post-conditioning, hearts received three 30 s cycles of ischaemia/reperfusion or levosimendan/vehicle. Hearts were pretreated with levosimendan immediately before CAL (without washout). Cardiac function, infarct size and reperfusion injury salvage kinase activity was assessed.

KEY RESULTS

LPC and LPostC halved the infarct size compared with controls (P<0.05). Treatment with K(ATP) channel blockers before LPC or LPostC reversed this decrease. Pretreating hearts with levosimendan increased activity of extracellular signal-regulated kinase (ERK) 42/44 on reperfusion and had the most marked infarct-lowering effect (P<0.05).

CONCLUSIONS AND IMPLICATIONS

(1) Hearts could be pharmacologically pre- and post-conditioned with levosimendan; (2) levosimendan pretreatment is the most effective way to reduce infarct size, possibly by increasing ERK 42/44 activity; (3) benefits of LPC and LPostC were abolished by both K(ATP) channel blockers and (4) LPC may be useful before elective cardiac surgery, whereas LPostC may be used after acute coronary artery events.

How should the efficacy of novel treatments be assessed in survival trials?

Survival trials tend to have the results presented in relative terms, usually using the hazard ratio. When absolute treatment effects are presented this is often done in terms of the Number Needed to Treat concept. For many medical treatments this approach is biologically implausible and can be misleading. The mean survival time approach leading to the absolute treatment effect in terms of extra life years is rarely used. It is suggested that this approach has many advantages over the Number Needed to Treat approach and should be used to present the absolute treatment effect in survival trials.

Reperfusion injury as a therapeutic challenge in patients with acute myocardial infarction

Cardiomyocyte death secondary to transient ischemia occurs mainly during the first minutes of reperfusion, in the form of contraction band necrosis involving sarcolemmal rupture. Cardiomyocyte hypercontracture caused by re-energisation and pH recovery in the presence of impaired cytosolic Ca(2+) control as well as calpain-mediated cytoskeletal fragility play prominent roles in this type of cell death. Hypercontracture can propagate to adjacent cells through gap junctions. More recently, opening of the mitochondrial permeability transition pore has been shown to participate in reperfusion-induced necrosis, although its precise relation with hypercontracture has not been established. Experimental studies have convincingly demonstrated that infarct size can be markedly reduced by therapeutic interventions applied at the time of reperfusion, including contractile blockers, inhibitors of Na(+)/Ca(2+) exchange, gap junction blockers, or particulate guanylyl cyclase agonists. However, in most cases drugs for use in humans have not been developed and tested for these targets, while the effect of existing drugs with potential cardioprotective effect is not well established or understood. Research effort should be addressed to elucidate the unsolved issues of the molecular mechanisms of reperfusion-induced cell death, to identify and validate new targets and to develop appropriate drugs. The potential benefits of limiting infarct size in patients with acute myocardial infarction receiving reperfusion therapy are enormous.