Age-related increase in mortality among patients with first myocardial infarctions treated with thrombolysis. The Investigators of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-2)

Arterial-ventricular coupling with aging and disease

Age is the dominant risk factor for cardiovascular diseases. Understanding the coupling between the left ventricle (LV) and arterial system, termed arterial-ventricular coupling (E(A)/E(LV)), provides important mechanistic insights into the complex cardiovascular system and its changes with aging in the absence and presence of disease. E(A)/E(LV) can be indexed by the ratio of effective arterial elastance (E(A); a measure of the net arterial load exerted on the LV) to left ventricular end-systolic elastance (E(LV); a load-independent measure of left ventricular chamber performance). Age-associated alterations in arterial structure and function, including diameter, wall thickness, wall stiffness, and endothelial dysfunction, contribute to a gradual increase in resting E(A) with age. Remarkably there is a corresponding increase in resting E(LV) with age, due to alterations to LV remodeling (loss in myocyte number, increased collagen) and function. These age-adaptations at rest likely occur, at least, in response to the age-associated increase in E(A) and ensure that E(A)/E(LV) is closely maintained within a narrow range, allowing for optimal energetic efficiency at the expense of mechanical efficacy. This optimal coupling at rest is also maintained when aging is accompanied by the presence of hypertension, and obesity, despite further increases in E(A) and E(LV) in these conditions. In contrast, in heart failure patients with either reduced or preserved ejection fraction, E(A)/E(LV) at rest is impaired. During dynamic exercise, E(A)/E(LV) decreases, due to an acute mismatch between the arterial and ventricular systems as E(LV) increases disproportionate compared to E(A) (≈200 vs. 40%), to ensure that sufficient cardiac performance is achieved to meet the increased energetic requirements of the body. However, with advancing age the reduction in E(A)/E(LV) during acute maximal exercise is blunted, due to a blunted increase E(LV). This impaired E(A)/E(LV) is further amplified in the presence of disease, and may explain, in part, the reduced cardiovascular functional capacity with age and disease. Thus, although increased stiffness of the arteries itself has important physiological and clinical relevance, such changes also have major implications on the heart, and vice versa, and the manner in the way they interact has important ramifications on cardiovascular function both at rest and during exercise. Examination of the alterations in arterial-ventricular coupling with aging and disease can yield mechanistic insights into the pathophysiology of these conditions and increase the effectiveness of current therapeutic interventions.

Aspirin in primary and secondary prevention in elderly adults revisited

Despite the frequency and long duration of aspirin use, its role in primary and secondary prevention in older adults is not well studied. This review takes a critical look at the available literature on aspirin efficacy in elderly adults, and some relevant guidelines for practicing physicians are suggested.

Effects of aging on isoflurane-induced and protein kinase A-mediated activation of ATP-sensitive potassium channels in cultured rat aortic vascular smooth muscle cells

Isoflurane activates protein kinase A (PKA) in vascular smooth muscle cells (VSMCs), which in turn activates ATP-sensitive potassium (K(ATP)) channels and causes vasodilation. The present study was undertaken to examine whether advanced age influences the effect of isoflurane on K(ATP) channel activity in cultured VSMCs. We used VSMCs obtained from 12- to 15-week-old (adult) and 24- to 25-month-old (aged) male Wistar rats. Electrophysiological experiments were performed using cell-attached and inside-out patch-clamp techniques to monitor the K(ATP) channel activity. Application of isoflurane or forskolin to the bath solution in cell-attached recordings induced a significant increase in K(ATP) channel activity in the VSMCs from the adult group. However, K(ATP) channel opening induced by isoflurane, but not forskolin, was significantly suppressed by aging. On the other hand, cell-free recordings showed similar pharmacologic sensitivity to the K(ATP) channel opener pinacidil, inward rectification, and unitary conductance (40–45 pS) between groups. In addition, direct K(ATP) channel activation by c-PKA in the inside-out patches was similar in both groups. Furthermore, increasing PKA activation in cell-attached patches by CPT-cAMP restored isoflurane's effects in the aged group. These results suggest that aging decreases isoflurane-induced PKA activation, resulting in attenuation of K(ATP) channel opening.

Age-related loss of cardiac preconditioning: impact of protein kinase A

Helium induces preconditioning (He-PC) by mitochondrial calcium-sensitive potassium (mK(Ca)) channel-activation, but this effect is lost in the aged myocardium. Both, the upstream signalling pathway of He-PC and the underlying mechanisms for an age-related loss of preconditioning are unknown. A possible candidate as upstream regulator of mK(Ca) channels is protein kinase A (PKA). We investigated whether 1) regulation of PKA is involved in He-PC and 2) regulation of PKA is age-dependent. Young (2-3 months) and aged (22-24 months) Wistar rats were randomised to eight groups (each n=8). All animals underwent 25 min regional myocardial ischemia and 120 min reperfusion. Control (Con, Age Con) animals were not further treated. Young rats inhaled 70% helium for 3×5 min (He-PC). The PKA-blocker H-89 (10 μg/kg) was administered with and without helium (He-PC+H-89, H-89). Furthermore, we tested the effect of direct activation of mK(Ca) channels with NS1619. The adenylyl cyclase activator forskolin (For) was administered in young (300 μg/kg) and aged animals (300 and 1000 μg/kg). He-PC reduced infarct size from 60±4% (Con) to 37±10% (p<0.05). Infarct size reduction was completely abolished by H-89 (58±5%; p<0.05), but H-89 alone had no effect (57±2%). NS1619 reduced infarct size in the same concentration in both, young and aged rats (35±6%; p<0.05 vs. Con and 34±8%; p<0.05 vs. Age Con). Forskolin in a concentration of 300 μg/kg reduced infarct size in young (37±6%; p<0.05) but not in aged rats (48±13%; n.s.). In contrast, 1000 μg/kg Forskolin reduced infarct size also in aged rats (28±3%; p<0.05). He-PC is mediated by activation of PKA. Alterations in PKA regulation might be an underlying mechanism for the age-dependent loss of preconditioning.

Comparison of one-year outcome of patients aged <75 years versus ≥75 years undergoing "rescue" percutaneous coronary intervention

The influence of age on the clinical results after rescue angioplasty (percutaneous coronary intervention [PCI]) has been poorly investigated. In the present study, we evaluated the outcome of 514 consecutive patients undergoing rescue PCI who were divided into 2 groups according to age: <75 years (n = 469) and ≥75 years (n = 45). The primary end point of the study was the incidence of death at 1 year of follow-up. The secondary end point was the 1-year incidence of major cardiac adverse events (MACE) defined as a composite of death, recurrent acute myocardial infarction, and target vessel revascularization. The predictors of death and MACE at 1 year were also investigated. At 1 year of follow-up, the <75-year-old group had a significantly lower incidence of death (7% vs 24%, p = 0.0001) and MACE (14% vs 28%, p = 0.01) compared to the ≥75-year-old group. The Cox proportional hazards model identified age (adjusted hazard ratio 0.2665, 95% confidence interval 0.1285 to 0.5524, p = 0.0004), cardiogenic shock (hazard ratio 0.1057, 95% confidence interval 0.0528 to 0.2117, p <0.000001), Thrombolysis In Myocardial Infarction flow grade 2 to 3 after PCI versus 0 to 1 (hazard ratio 3.8380, 95% confidence interval 1.7781 to 8.2843, p = 0.0006), multi- versus single-vessel disease (hazard ratio 0.3716, 95% confidence interval 0.1896 to 0.7284, p = 0.0039) as independent predictors of survival at 1 year of follow-up. In conclusion, at 1 year of follow-up after rescue PCI, the patients aged ≥75 years had a greater incidence of death and MACE compared to patients aged <75 years. Age, cardiogenic shock, Thrombolysis In Myocardial Infarction flow grade 0-1 after PCI, and multivessel coronary disease were predictors of survival and freedom from MACE at 1 year of follow-up.

Ischemia/Infarction

Myocardial infarction (MI) accounts for most incidences of heart failure (HF) and low ejection fraction. Evidence suggests that acute MI leads to early cardiac remodeling, with changes in ventricular geometry and structure that in turn lead to a vicious cycle of ventricular dilation, increased wall stress, hypertrophy and more ventricular dilation and dysfunction, and worsening of HF. The early geometric and structural changes contribute to early mechanical complications and subsequent progressive ventricular remodeling and the development of chronic HF. A clear understanding of the underlying mechanisms is helpful in developing optimal preventive and therapeutic strategies for HF.

The impact of age on effects of pre-hospital initiation of high bolus dose of tirofiban before primary angioplasty for ST-elevation myocardial infarction

PURPOSE

Glycoprotein IIb/IIIa inhibitors are favourable in ST-elevation myocardial infarction (STEMI) patients, and the additional value of early pre-hospital high bolus dose tirofiban has recently been established. The aim of this study was to determine the impact of age on myocardial reperfusion and clinical outcomes of pre-hospital administration of high bolus dose tirofiban.

METHODS

This is a pre-specified sub-analysis of the multicentre, double-blind, placebo-controlled, randomised On-TIME 2 trial and it's open label phase. The primary endpoint was mean residual ST segment deviation 1 h after primary PCI and was evaluated in three age groups.

RESULTS

Of the 466 patients in the highest tertile (≥68 years), median age was 74.4 years (IQR 71.3-78.6 years) and 231 (50%) were randomised to tirofiban. Mean residual ST segment deviation 1 h after PCI was significantly lower in elderly patients pre-treated with tirofiban compared to elderly patients without tirofiban pre-treatment (4.2 ± 5.2 mm vs 6.4 ± 7.5 mm, p = 0.001). Furthermore, elderly patients pre-treated with tirofiban had a non-significantly higher rate of 30-day major or minor bleeding compared to elderly patients without tirofiban pre-treatment (14.2% vs 9.0%, p = 0.088). 30-day net adverse clinical events in elderly patients with- or without tirofiban was not significantly different (11.9% vs 15.2%, p = 0.300).

CONCLUSION

The effect of pre-hospital initiation of high bolus dose tirofiban on myocardial reperfusion, as determined by ST-segment resolution is highest in the elderly patients. However, this was associated with a trend towards more bleeding complications, resulting in a balanced clinical effect after 30-day follow-up. Future studies should evaluate whether the elderly STEMI patient may benefit from highly effective and safer antiplatelet therapy.

Caloric restriction primes mitochondria for ischemic stress by deacetylating specific mitochondrial proteins of the electron transport chain

RATIONALE

Caloric restriction (CR) confers cardioprotection against ischemia/reperfusion injury. However, the exact mechanism(s) underlying CR-induced cardioprotection remain(s) unknown. Recent evidence indicates that Sirtuins, NAD(+)-dependent deacetylases, regulate various favorable aspects of the CR response. Thus, we hypothesized that deacetylation of specific mitochondrial proteins during CR preserves mitochondrial function and attenuates production of reactive oxygen species during ischemia/reperfusion.

OBJECTIVE

The objectives of the present study were (1) to investigate the effect of CR on mitochondrial function and mitochondrial proteome and (2) to investigate what molecular mechanisms mediate CR-induced cardioprotection.

METHODS AND RESULTS

Male 26-week-old Fischer344 rats were randomly divided into ad libitum-fed and CR (40% reduction) groups for 6 months. No change was observed in basal mitochondrial function, but CR preserved postischemic mitochondrial respiration and attenuated postischemic mitochondrial H(2)O(2) production. CR decreased the level of acetylated mitochondrial proteins that were associated with enhanced Sirtuin activity in the mitochondrial fraction. We confirmed a significant decrease in the acetylated forms of NDUFS1 and cytochrome bc1 complex Rieske subunit in the CR heart. Low-dose resveratrol treatment mimicked the effect of CR on deacetylating them and attenuated reactive oxygen species production during anoxia/reoxygenation in cultured cardiomyocytes without changing the expression levels of manganese superoxide dismutase. Treatment with nicotinamide completely abrogated the effect of low-dose resveratrol.

CONCLUSIONS

These results strongly suggest that CR primes mitochondria for stress resistance by deacetylating specific mitochondrial proteins of the electron transport chain. Targeted deacetylation of NDUFS1 and/or Rieske subunit might have potential as a novel therapeutic approach for cardioprotection against ischemia/reperfusion.

The role of inflammatory and fibrogenic pathways in heart failure associated with aging

Heart failure is strongly associated with aging. Elderly patients with heart failure often have preserved systolic function exhibiting left ventricular hypertrophy accompanied by a decline in diastolic function. Experimental studies have demonstrated that age-related cardiac fibrosis plays an important role in the pathogenesis of diastolic heart failure in senescent hearts. Reactive oxygen species and angiotensin II are critically involved in fibrotic remodeling of the aging ventricle; their fibrogenic actions may be mediated, at least in part, through transforming growth factor (TGF)-beta. The increased prevalence of heart failure in the elderly is also due to impaired responses of the senescent heart to cardiac injury. Aging is associated with suppressed inflammation, delayed phagocytosis of dead cardiomyocytes, and markedly diminished collagen deposition following myocardial infarction, due to a blunted response of fibroblasts to fibrogenic growth factors. Thus, in addition to a baseline activation of fibrogenic pathways, senescent hearts exhibit an impaired reparative reserve due to decreased responses of mesenchymal cells to stimulatory signals. Impaired scar formation in senescent hearts is associated with accentuated dilative remodeling and worse systolic dysfunction. Understanding the pathogenesis of interstitial fibrosis in the aging heart and dissecting the mechanisms responsible for age-associated healing defects following cardiac injury are critical in order to design new strategies for prevention of adverse remodeling and heart failure in elderly patients.

Intravenous erythropoietin in patients with ST-segment elevation myocardial infarction: REVEAL: a randomized controlled trial

CONTEXT

Acute ST-segment elevation myocardial infarction (STEMI) is a leading cause of morbidity and mortality. In experimental models of MI, erythropoietin reduces infarct size and improves left ventricular (LV) function.

OBJECTIVE

To evaluate the safety and efficacy of a single intravenous bolus of epoetin alfa in patients with STEMI.

DESIGN, SETTING, AND PATIENTS

A prospective, randomized, double-blind, placebo-controlled trial with a dose-escalation safety phase and a single dose (60,000 U of epoetin alfa) efficacy phase; the Reduction of Infarct Expansion and Ventricular Remodeling With Erythropoietin After Large Myocardial Infarction (REVEAL) trial was conducted at 28 US sites between October 2006 and February 2010, and included 222 patients with STEMI who underwent successful percutaneous coronary intervention (PCI) as a primary or rescue reperfusion strategy.

INTERVENTION

Participants were randomly assigned to treatment with intravenous epoetin alfa or matching saline placebo administered within 4 hours of reperfusion.

MAIN OUTCOME MEASURE

Infarct size, expressed as percentage of LV mass, assessed by cardiac magnetic resonance (CMR) imaging performed 2 to 6 days after study medication administration (first CMR) and again 12 ± 2 weeks later (second CMR).

RESULTS

In the efficacy cohort, the infarct size did not differ between groups on either the first CMR scan (n = 136; 15.8% LV mass [95% confidence interval {CI}, 13.3-18.2% LV mass] for the epoetin alfa group vs 15.0% LV mass [95% CI, 12.6-17.3% LV mass] for the placebo group; P = .67) or on the second CMR scan (n = 124; 10.6% LV mass [95% CI, 8.4-12.8% LV mass] vs 10.4% LV mass [95% CI, 8.5-12.3% LV mass], respectively; P = .89). In a prespecified analysis of patients aged 70 years or older (n = 21), the mean infarct size within the first week (first CMR) was larger in the epoetin alfa group (19.9% LV mass; 95% CI, 14.0-25.7% LV mass) than in the placebo group (11.7% LV mass; 95% CI, 7.2-16.1% LV mass) (P = .03). In the safety cohort, of the 125 patients who received epoetin alfa, the composite outcome of death, MI, stroke, or stent thrombosis occurred in 5 (4.0%; 95% CI, 1.31%-9.09%) but in none of the 97 who received placebo (P = .04).

CONCLUSIONS

In patients with STEMI who had successful reperfusion with primary or rescue PCI, a single intravenous bolus of epoetin alfa within 4 hours of PCI did not reduce infarct size and was associated with higher rates of adverse cardiovascular events. Subgroup analyses raised concerns about an increase in infarct size among older patients.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00378352.

The aging heart and post-infarction left ventricular remodeling

Aging is a risk factor for heart failure, which is a leading cause of death world-wide. Elderly patients are more likely than young patients to experience a myocardial infarction (MI) and are more likely to develop heart failure following MI. The poor clinical outcome of aging in cardiovascular disease is recapitulated on the cellular level. Increase in stress exposure and shifts in signaling pathways with age change the biology of cardiomyocytes. The progressive accumulation of metabolic waste and damaged organelles in cardiomyocytes blocks the intracellular recycling process of autophagy and increases the cell's propensity toward apoptosis. Additionally, the decreased cardiomyocyte renewal capacity in the elderly, due to reduction in cellular division and impaired stem cell function, leads to further cardiac dysfunction and maladaptive responses to disease or stress. We review the cellular and molecular aspects of post-infarction remodeling in the aged heart, and relate them to the clinical problem of post-infarction remodeling in elderly patients.

Acute glucose dysmetabolism in the elderly with ST elevation myocardial infarction submitted to mechanical revascularization

Though age is a predictor of adverse events after acute coronary syndrome, including in-hospital and post-hospital mortality rates, elderly patients are under-represented in randomized trials evaluating strategies of early coronary revascularization in acute myocardial infarction. Several factors can account for the unfavorable outcome of the elderly, comprising increased glucose values. Diabetes is more common in the elderly patients with acute myocardial infarction in respect to younger patients and elevated glucose, though common, are rarely treated and associated with increased mortality, particularly in those without recognized diabetes. Age itself is thought to affect the acute glucose response to stress. Human aging is associated with impaired β-cell sensitivity to glucose and impaired β-cell compensation to insulin resistance and older people exhibit an impaired glucose response after injury characterized by a more marked increases in endogenous glucose production. In the early phase of ST elevation myocardial infarction (STEMI), the acute glucose response to stress comprises not only hyperglycemia but also insulin-resistance (assessed by the Homeostatic Model Assessment). Recently it has been documented in 346 STEMI patients submitted to mechanical revascularization that the acute glucose response to myocardial injury differs in respect to age, since older patients showed the highest glucose levels and the poorest glycemic control during ICCU stay in the lack of differences in insulin resistance incidence. Taking into account that aging impairs the acute glucose response to stress in elderly STEMI patients, further studies are needed to establish whether a different (more aggressive) therapeutic regime is needed in this subgroup of patients at higher risk.

Predictors of the early outcome in elderly patients with ST elevation myocardial infarction treated with primary angioplasty: a single center experience

Elderly patients are under-represented in trials assessing strategies of early coronary revascularization in acute myocardial infarction, though they are the fastest growing segment of our population. The aims of the present investigation, performed in 357 elderly (≥75 years) patients with ST elevation myocardial infarction (STEMI) submitted to primary percutaneous coronary intervention (PCI) consecutively admitted to our Intensive Cardiac Care Unit (ICCU) from 1 January 2006 to 31 December 2009, were as follows: (a) to identify predictors for in-ICCU mortality among clinical, angiographic and metabolic factors and (b) to evaluate whether there are gender-related differences in management, outcome and in the metabolic and inflammatory responses to acute myocardial ischemia. At multivariable backward stepwise logistic regression analysis, the following variables were independent predictors for in-ICCU mortality in the overall population: age (OR 1.15; 95% CI 1.05-1.27; p < 0.003), admission glycemia (OR 2.24; 95% CI 1.41-3.56; p < 0.001), left ventricular ejection fraction (LVEF) (OR 0.92; 95% CI 0.88-0.97; p < 0.001), primary PCI failure (OR 4.70; 95% CI 1.70-12.98; p < 0.003). In elderly STEMI patients submitted to primary PCI, early mortality can be related to age, hemodynamic derangement (as indicated by LVEF), the rate of procedural success, and increased glucose values. No gender-related differences in management were detectable in our series. Our data strongly suggest that, in elderly patients in the acute phase of STEMI, since hyperglycemia is a modifying factor, glucose values deserve a more intensive treatment. Further studies, performed specifically in elderly STEMI patients, should be addressed to identify the glucose cut-off values able to influence the outcome.

Deficiency in TIMP-3 increases cardiac rupture and mortality post-myocardial infarction via EGFR signaling: beneficial effects of cetuximab

Cardiac rupture is a fatal complication of myocardial infarction (MI); however, its underlying molecular mechanisms are not fully understood. This study investigated the role of tissue inhibitor of metalloproteinase-3 (TIMP-3)/matrix metalloproteinase (MMP)/epidermal growth factor (EGF)/transforming growth factor (TGF)-β1 pathway in infarct healing and effects of cetuximab on cardiac rupture after MI. Induction of MI was achieved by left coronary artery ligation in wild-type (WT) and TIMP-3(-/-) mice. TIMP-3 deficiency resulted in a fourfold increase in cardiac rupture and 50% decrease in survival after MI. Hydroxyproline content, collagen synthesis and myofibroblast cell number in the infarct region, and the force required to induce rupture of the infarct scar were significantly decreased, while MMP activity was increased in TIMP-3(-/-) mice. EGF proteins were increased by threefold in TIMP-3(-/-) mice following MI, while TGF-β1 mRNA levels were decreased by 68%. Cell proliferation of cultured adult cardiac myofibroblasts was significantly decreased in TIMP-3(-/-) compared to WT myofibroblasts. EGF treatment significantly decreased collagen synthesis and TGF-β1 expression. Conversely, TGF-β1 treatment increased collagen synthesis in cardiac myofibroblasts. Treatment with cetuximab significantly decreased the incidence of cardiac rupture and improved survival post-MI in TIMP-3(-/-) mice. We conclude that deficiency in TIMP-3 increases cardiac rupture post-MI via EGF/epidermal growth factor receptor (EGFR) signaling which downregulates TGF-β1 expression and collagen synthesis. Inhibition of EGFR by cetuximab protects against cardiac rupture and improves survival post-MI.

Cardiovascular protection afforded by caloric restriction: essential role of nitric oxide synthase

Caloric restriction is an established intervention, of which anti-aging effects are scientifically proven. It has pleiotropic effects on the cardiovascular system: vascular protection, improvement of myocardial ischemic tolerance and retardation of cardiac senescence. First, increasing evidence from both experimental and clinical studies supports the concept that "a man is as old as his arteries". Caloric restriction could prevent the progression of atherosclerosis and vascular aging through direct and indirect mechanisms. Second, the hearts of senescent animals are more susceptible to ischemia than those of young animals. We demonstrated that short-term and prolonged caloric restriction confers cardioprotection against ischemia/reperfusion injury in young and aged rodents. Furthermore, we showed that the increase in circulating adiponectin levels and subsequent activation of adenosine monophosphate-activated protein kinase are necessary for the cardioprotection afforded by short-term caloric restriction. In contrast, the mechanisms by which prolonged caloric restriction confers cardioprotection seem more complicated. Adiponectin, nitric oxide synthase and sirtuin may form a network of cardiovascular protection during caloric restriction. Recently, by using genetically engineered mice, we found that, in addition to endothelial nitric oxide synthase, neuronal nitric oxide synthase plays an essential role in the development of cardioprotection afforded by prolonged caloric restriction. Third, long-term caloric restriction has cardiac-specific effects that attenuate the age-associated impairment seen in left ventricular diastolic function. It is possible that long-term caloric restriction partially retards cardiac senescence by attenuating oxidative damage in the aged heart. Overall, we strongly believe that caloric restriction could reduce morbidity and mortality of cardiovascular events in humans.

Caring of ST-elevation myocardial infarction patients in rural community hospital settings: determinants of in-hospital mortality

OBJECTIVE

Cardiovascular disease contributes more than three quarters of all cardiovascular deaths worldwide. Adherence to myocardial infarction (MI) guidelines might not be possible in many rural hospitals. We aim to share our three-year experience in rural settings regarding to ST-elevation MI (STEMI) patients particularly by focusing on determinants of in-hospital mortality.

METHODS

We retrospectively analysed our data for 559 acute STEMI patients admitted to our coronary care unit in Kastamonu city, Turkey between August 2004 and August 2007. Key demographic and clinical characteristics and data regarding symptom duration, prehospital transfer settings and insurance status were collected. Killip classes and in-hospital therapy of all patients were recorded.

RESULTS

A total of 54 patients (9.66%) died within the hospitalisation period. Multivariate analysis revealed that advanced age > 65 years, late admission, hypotension at presentation, killip class > 2, anterior location, posterior location, lack of fibrinolysis and cardiogenic shock were independent predictors of in-hospital mortality.

CONCLUSIONS

In rural hospital settings, clinical resources and transfer facilities are limited. Therefore, improvement of early transfer and prehospital fibrinolysis capabilities should decrease mortality.

Evaluation of the influence of age and gender on the relationships between infarct size, infarct severity, and left ventricular ejection fraction in patients successfully treated with primary percutaneous coronary intervention

BACKGROUND

Female sex and advanced age have adverse prognostic meaning in acute myocardial infarction. Whether gender and/or age influence the relationship between infarct size, infarct severity, and left ventricular ejection fraction (LVEF) is unclear.

METHODS

We examined 460 patients (359 men) with acute myocardial infarction submitted to successful primary percutaneous coronary intervention. Infarct size, infarct severity, and LVEF were evaluated with perfusion gated SPECT at one month of index infarction.

RESULTS

There were no significant correlations between age and infarct size or infarct severity, and between age and LVEF. Moreover, elderly age (>or=75 years) did not influence the relationship between LVEF and infarct size or infarct severity. Conversely, there was a significant gender-related difference in the relationship between LVEF and infarct size (F = 20.5, P < .00001), and between LVEF and infarct severity (F = 8.6, P < .005). In practice, there was a steeper decrease in LVEF in case of moderate to large infarct size in women than in men.

CONCLUSION

With increasing infarct size, LVEF decreases more sharply in women than in men. Conversely, age does not influence the relationship between infarct dimensions and LVEF.

Ischemic preconditioning in the aging heart: from bench to bedside

Coronary artery disease is the leading cause of death in industrialized countries for people older than 65 years of age. The reasons are still unclear. A reduction of endogenous mechanisms against ischemic insults has been proposed to explain this phenomenon. Cardiac ischemic preconditioning represents the most powerful endogenous protective mechanism against ischemia. Brief episodes of ischemia are able to protect the heart against a following more prolonged ischemic period. This protective mechanism seems to be reduced with aging both in experimental and clinical studies. Alterations of mediators release and/or intracellular pathways may be responsible for age-related ischemic preconditioning reduction. Opposite studies are questionable for the experimental model used, the timing of ischemic preconditioning, and the selection of elderly patients. Several pharmacological stimuli failed to mimic ischemic preconditioning in the aging heart but exercise training and caloric restriction separately, and more powerfully taken together, are able to completely preserve and/or restore the age-related reduction of ischemic preconditioning.

Factors related to heart rupture in acute coronary syndromes in the Global Registry of Acute Coronary Events

AIMS

To determine the incidence and factors associated with heart rupture (HR) in acute coronary syndrome (ACS) patients.

METHODS AND RESULTS

Among 60 198 patients, 273 (0.45%) had HR (free wall rupture, n = 118; ventricular septal rupture, n = 155). Incidence was 0.9% for ST-segment elevation myocardial infarction (STEMI), 0.17% for non-STEMI, and 0.25% for unstable angina. Hospital mortality was 58 vs. 4.5% in patients without HR (P < 0.001). The incidence was lower in STEMI patients with primary percutaneous coronary intervention (PCI) than in those without (0.7 vs. 1.1%; P = 0.01), but primary PCI was not independently related to HR in adjusted analysis (P = 0.20). Independent variables associated with HR included: ST-segment elevation (STE)/left bundle branch block; ST-segment deviation; female sex; previous stroke; positive initial cardiac biomarkers; older age; higher heart rate; systolic blood pressure/30 mmHg decrease. Conversely, previous MI and the use of low-molecular-weight heparin and beta-blockers during first 24 h were identified as protective factors for HR.

CONCLUSION

The incidence of HR is low in patients with ACS, although its incidence is probably underestimated. Heart rupture occurs more frequently in ACS with STE and is associated with high hospital mortality. A number of variables are independently related to HR.

Cardiac rupture after myocardial infarction: new insights from murine models

Cardiac rupture after a myocardial infarction is an uncommon event with devastating consequences. Although the clinical features of rupture have been described, the genetic and molecular influences on this outcome in patients are less certain. In mice, at least 17 genetic models have been developed that enhance or suppress the likelihood of rupture postmyocardial infarction. The purpose of this review is to describe these recent advances, recognizing that nearly all of the information has been obtained from mouse models of free wall rupture. Although it is probable that the same genetic determinants apply to septal and papillary muscle rupture, the possibility remains that there are unique modulators of risk for rupture at differing anatomic sites within the heart. It is likely that the candidate genes also influence rupture in humans, although this conclusion must be confirmed. The mouse models will be helpful to direct future proteomic and genomic studies in patients and may already suggest certain fundamental pathways. For example, the essential role of collagen production and stabilization postmyocardial infarction may direct therapies to enhance collagen cross-linking and limit its degradation as a strategy to reduce rates of rupture and enhance myocardial healing.

Acute left ventricular rupture following posterior wall myocardial infarction

Free wall rupture, the most fearful complication of myocardial infarction, mostly attacks anterior walls. Acute rupture is characterized by rapid development of mechanical arrest accompanied with bradyarrhythmia or electromechanical dissociation. The majority of patients succumb to death as the result of cardiac tamponade. Risk factors are advanced age, female gender, the first-time myocardial infarction, hypertension, and ST-segment elevation. We report a rare case of posterior wall myocardial infarction complicated with left ventricular rupture initially presenting with junctional escape rhythm.

Comparison of effects of primary coronary angioplasty on left ventricular remodeling and heart failure in patients <70 versus > or =70 years with acute myocardial infarction

Experimental studies have demonstrated the adverse effects of senescence on cardiac function and remodeling after acute myocardial infarction (AMI). We sought to assess the impact of age on left ventricular (LV) remodeling and heart failure (HF) after successful primary angioplasty for AMI. A series of 512 consecutive patients underwent 2-dimensional echocardiography at admission and at 1 month and 6 months after index AMI. LV volumes, ejection fraction, and wall motion score index (WMSI) were measured. Patients were divided in group 1 (<70 years old, n = 361) and group 2 (> or =70 years old, n = 151). Group 2 patients showed a lower peak creatine kinase (p = 0.029) compared to group 1. In group 2 patients the 6-month prevalence of LV remodeling (increase >20% in end-diastolic volume) was higher (34% vs 25%, p = 0.041), recoveries of ejection fraction and WMSI were lower (p = 0.00002 for the 2 comparisons), and incidence of late HF was higher (35% vs 17%, p <0.0001) compared to group 1 patients. Independent predictors of LV remodeling were WMSI (p <0.0001), infarct size (p <0.0001), and LV end-diastolic volume (p <0.0001). Independent predictors of late HF were WMSI (hazard ratio [HR] 2.7, 95% confidence interval [CI] 1.624 to 4.514), 6-month LV dilation (HR 2.13, 95% CI 1.404 to 3.233), diabetes (HR 1.6, 95% CI 1.008 to 2.595), infarct size (HR 1.12, 95% CI 1.037 to 1.215), and age as continuous variables (HR 1.064, 95% CI 1.044 to 1.085). In conclusion, besides infarct size, extensive regional systolic dysfunction may play a significant role in the development of LV remodeling and HF in patients > or =70 years old after successful primary angioplasty.

Effects of perindopril on cardiac remodelling and prognostic value of pre-discharge quantitative echocardiographic parameters in elderly patients after acute myocardial infarction: the PREAMI echo sub-study

AIMS

To determine (i) the effect of perindopril on several geometric and functional parameters of the left and right ventricles assessed by echocardiography in the unique Perindopril and Remodelling in Elderly with Acute Myocardial Infarction (PREAMI) population of post-acute myocardial infarction (AMI) elderly patients with preserved left ventricular (LV) function; and (ii) the prognostic predictors at pre-discharge derived from echo-Doppler measurements in the same population.

METHODS AND RESULTS

PREAMI included 1252 post-AMI patients (age 73 +/- 6 years, LV ejection fraction 59.1 +/- 7.7%) receiving optimal therapy after AMI, randomized to perindopril 8 mg/day (n = 631) or placebo (n = 621); n = 896 had complete echo-Doppler data. Outcome measures were clinical [death, heart failure (HF)] and standard echo-Doppler parameters. Pre-discharge LV end-diastolic volume (LVEDV) was similar: 81.1 +/- 23.1 (perindopril) and 79.6 +/- 22.7 mL (placebo). At 6 months and 1 year, LVEDV remained unchanged with perindopril (81.2 +/- 24.4 and 81.8 +/- 26.8 mL, respectively), but increased with placebo (83.0 +/- 25.3 and 83.6 +/- 25.7 mL, respectively, both P < 0.001 vs. baseline). Perindopril reduced cardiac sphericity vs. placebo (P = 0.015 at 6 months; P = 0.020 at 1 year). Classification regression tree analysis showed treatment as the most important predictor of remodelling. Multiple pre-discharge echocardiographic variables predicted the death/HF endpoint, independently of treatment (P < or = 0.05).

CONCLUSION

Remodelling occurs in post-AMI in elderly patients with normal LV function. Echo-Doppler variables at baseline have prognostic implications. Treatment with perindopril reduces progressive LV remodelling that can occur even in the case of small infarct size.

In-hospital mortality of elderly patients with acute myocardial infarction: data from the MITRA (Maximal Individual Therapy in Acute Myocardial Infarction) registry

BACKGROUND

Advanced age remains one of the principal determinants of mortality in patients with acute myocardial infarction (AMI).

HYPOTHESIS

The aim of this study was to determine the in-hospital outcome of elderly (> 75 years) patients with AMI who were admitted to hospitals participating in the national MITRA (Maximal Individual Therapy in Acute Myocardial Infarction) registry.

METHODS

MITRA is a prospective, observational German multicenter registry investigating current treatment modalities for patients presenting with AMI. All patients with AMI admitted within 96 h of onset of symptoms were included in the MITRA registry. MITRA was started in June 1994 and ended in January 1997. This registry comprises 6,067 consecutive patients with a mean age of 65 +/- 12 years, of whom 1,430 (17%) were aged > 75 years. Patients were compared with respect to patient characteristics, prehospital delays, early treatment strategies, and clinical outcome.

RESULTS

In the elderly patient population, the prehospital delay was 210 min, which was significantly longer than that for younger patients (155 min, p = 0.001). Although the incidence of potential contraindications for the initiation of thrombolysis was almost equally distributed between the two age groups (8.7 vs. 8.2%, p = NS), elderly patients (> 75 years) received reperfusion therapy less frequently (35.9 vs. 64.6%) than younger patients. Mortality increased with advanced age and was 26.4% for all patients aged > 75 years. If reperfusion therapy was initiated, in-hospital mortality was 21.8 versus 28.9% in patients aged > 75 years (p = 0.001) and 29.4 versus 38.5% in patients aged > 85 years (p = 0.001).

CONCLUSION

In this registry, elderly patients with AMI had a much higher in-hospital mortality than that expected from randomized trials. In MITRA, the mortality reduction with reperfusion therapy was found to be highest in the very elderly patient population.

Outcomes and quality of life in patients>or=85 years of age with ST-elevation myocardial infarction

The oldest old comprise the fastest growing segment of the US population. However, data are limited regarding the treatment and outcomes of ST-segment elevation myocardial infarction (STEMI) in this age group. We analyzed consecutive patients with STEMI>or=85 years old at a single center. Quality of life was assessed using the EQ-5D Index (range -0.11 to 1.00) and EQ-VAS (range 0 to 100). Of 1,847 patients admitted from 2002 to 2007 with STEMI, 73 (4%) were >or=85 years old (range 85 to 94). Median time from symptom onset to hospital arrival was 3 hours. Cardiogenic shock occurred in 33%. Primary percutaneous coronary intervention (PCI) was performed in 70% of patients, and the procedural success rate was 94%. Evidenced-based therapy included aspirin (97%), clopidogrel (93%), beta blockers (82%), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (74%), and statins (86%). The in-hospital mortality rate was 32%, and it was 54% in those with cardiogenic shock. Long-term follow-up was obtained in 96% of hospital survivors at a median of 429 days. Survival rates in patients discharged alive were 75% at 1 year and 65% at 2 years. Cardiogenic shock was the only independent predictor of in-hospital mortality (odds ratio 3.8, 95% confidence interval 1.2 to 11.7, p=0.02), and primary PCI was the only independent predictor of long-term survival (hazard ratio 0.3, 95% confidence interval 0.1 to 0.8, p=0.02). Mean EQ-5D Index was 0.78 and mean EQ-VAS was 70.5. In conclusion, in the oldest old with STEMI, aggressive treatment is associated with reasonable long-term survival and excellent quality of life. The exception may be patients presenting with cardiogenic shock, for whom short-term mortality remains exceedingly high.

Role of healing-specific-matricellular proteins and matrix metalloproteinases in age-related enhanced early remodeling after reperfused STEMI in dogs

We assessed whether aging augments left ventricular (LV) damage, remodeling, and dysfunction and alters expression of healing-specific-matricellular proteins (HSMPs), matrix metalloproteinases (MMPs) and other pertinent proteins after acute reperfused-ST-segment-elevation myocardial infarction (RSTEMI) in the dog model. The findings suggest a novel role for HSMPs, MMPs, and the other proteins in the age-related increase in LV damage, remodeling, and dysfunction. Potentially detrimental effects of the altered proteins appear to outweigh beneficial effects and contribute to adverse outcome. Deleterious changes include the increase in matrix-degrading MMPs, inducible nitric oxide synthase (iNOS) and pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha, HSMPs such as secreted-protein-acidic-and-rich-in-cysteine (SPARC) and osteopontin (OPN), the blunted increase in endothelial-NOS (eNOS), and the decrease in IL-10 and neuronal NOS (nNOS). Potentially beneficial changes include increases in the HSMP secretory-leucocyte-protease-inhibitor (SLPI) and cytokine transforming growth factor (TGF)-beta(1). Targeting these proteins may mitigate enhanced LV remodeling and dysfunction with aging.

Impact of 6-mo caloric restriction on myocardial ischemic tolerance: possible involvement of nitric oxide-dependent increase in nuclear Sirt1

Ischemic tolerance decreases with aging, and the cardioprotective effect of ischemic preconditioning (IPC) is impaired in middle-aged animals. We have demonstrated that short-term caloric restriction (CR) improves myocardial ischemic tolerance in young and old animals via the activation of adiponectin-AMP-activated protein kinase (AMPK)-mediated signaling. However, it is unknown whether prolonged CR confers cardioprotection in a similar manner. Furthermore, little is known regarding the myocardial expression of silent information regulator 1 (Sirt1; which reportedly mediates various aspects of the CR response) with prolonged CR. Thus, 6-mo-old male Fischer-344 rats were randomly divided into ad libitum (AL) and CR groups. Six months later, isolated perfused hearts were subjected to 25 min of global ischemia followed by 120 min of reperfusion with or without IPC. CR improved the recovery of left ventricular function and reduced infarct size after ischemia-reperfusion and restored the IPC effect. Serum adiponectin levels increased, but myocardial levels of total and phosphorylated AMPK did not change with prolonged CR. Total levels of Sirt1 did not change with CR; however, in the nuclear fraction, CR significantly increased Sirt1 and decreased acetyl-histone H3. Eleven rats from each group were given N-nitro-l-arginine methyl ester in their drinking water for 4 wk before death. In these hearts, chronic inhibition of nitric oxide synthase prevented the increase in nuclear Sirt1 content by CR and abrogated CR-induced cardioprotection. These results demonstrate that 1) prolonged CR improves myocardial ischemic tolerance and restores the IPC effect in middle-aged rats and 2) CR-induced cardioprotection is associated with a nitric oxide-dependent increase in nuclear Sirt1 content.

Attenuation of isoflurane-induced preconditioning and reactive oxygen species production in the senescent rat heart

BACKGROUND

Although attenuation of anesthetic preconditioning in aged ex vivo heart models has been studied extensively, there are no comparable in vivo studies. To extend previous work and to address a possible mechanism underlying age-related differences, we investigated isoflurane-induced preconditioning and reactive oxygen species (ROS) production in the aged rat heart in vivo.

METHODS

Male Fisher 344 rats were assigned from their respective age groups (young, 3-5 mo; old, 20-24 mo) to either receive 30 min of 1.0 minimum alveolar concentration isoflurane or to a control group. Rats were subjected to coronary artery occlusion for 30 min followed by 2 h of reperfusion. A fluorescent probe for superoxide anion production (dihydroethidium, 1 mg) was administered in the absence of the isoflurane or just before isoflurane exposure in four additional groups. Myocardial infarct size and superoxide anion production were assessed using triphenyltetrazolium staining and epifluorescence microscopy, respectively.

RESULTS

Isoflurane decreased myocardial infarct size of young rats (26.7% +/- 3.0%) compared with young controls (50.9% +/- 1.9%; P < 0.001), whereas isoflurane did not significantly affect myocardial infarct size of old rats (39.1% +/- 0.9%) compared with old controls (46.5% +/- 2.4%; P > 0.05). Isoflurane increased ROS levels in young rats (430.5 +/- 95.9 arbitrary units [AU]) compared with young controls (162.7 +/- 25.5 AU; P < 0.01). In contrast, no significant changes in ROS levels were observed in old animals (316.4 +/- 56.3 AU isoflurane versus 233.8 +/- 59.2 AU control).

CONCLUSIONS

Reduction in the cardioprotective effects of isoflurane and attenuation of isoflurane-stimulated ROS production were observed in the senescent myocardium in vivo.

Simulated ischemia-induced preconditioning of isolated ventricular myocytes from young adult and aged Fischer-344 rat hearts

The impact of ischemic preconditioning (IPC) on contraction, Ca(2+) homeostasis, and cell survival was compared in isolated ventricular myocytes from young adult ( approximately 3 mo) and aged ( approximately 24 mo) male Fischer-344 rats. Myocytes were field stimulated at 4 Hz (37 degrees C). Contraction (edge detector) and intracellular Ca(2+) (fura-2) were measured simultaneously. Viability was assessed with trypan blue. All cells were exposed to 30 min of simulated ischemia followed by reperfusion. Some cells were preconditioned by exposure to 5 min of simulated ischemia before prolonged ischemia. Pretreatment with IPC abolished postischemic contractile depression, inhibited diastolic contracture, and increased Ca(2+) transient amplitudes in reperfusion in young adult and aged cells. IPC did not affect the modest rise in diastolic Ca(2+) in ischemia in young adult myocytes. However, IPC abolished the marked rise in diastolic Ca(2+) observed in ischemia and early reperfusion in aged myocytes. IPC also suppressed mechanical alternans in ischemia in aged cells, but younger myocytes showed little evidence of mechanical alternans whether or not cells were preconditioned. IPC markedly improved cell viability in reperfusion in young adult but not aged cells. These results suggest that IPC augments the recovery of contractile function in reperfusion by increasing Ca(2+) transient amplitudes in ventricular myocytes from young adult and aged rats. IPC reduced diastolic Ca(2+) accumulation in ischemia in aged myocytes, which may diminish the severity of mechanical alternans in aged cells. Nonetheless, the efficacy of IPC is compromised in aging, as IPC did not improve survival of aged myocytes exposed to ischemia and reperfusion.

Aging-related defects are associated with adverse cardiac remodeling in a mouse model of reperfused myocardial infarction

OBJECTIVES

The purpose of this study was to study aging-associated alterations in the inflammatory and reparative response after myocardial infarction (MI) and their involvement in adverse post-infarction remodeling of the senescent heart.

BACKGROUND

Advanced age is a predictor of death and ventricular dilation in patients with MI; however, the cellular mechanisms responsible for increased remodeling of the infarcted senescent heart remain poorly understood.

METHODS

Histomorphometric, molecular, and echocardiographic end points were compared between young and senescent mice undergoing reperfused infarction protocols. The response of young and senescent mouse cardiac fibroblasts to transforming growth factor (TGF)-beta stimulation was examined.

RESULTS

Senescence was associated with decreased and delayed neutrophil and macrophage infiltration, markedly reduced cytokine and chemokine expression in the infarcted myocardium, and impaired phagocytosis of dead cardiomyocytes. Reduced inflammation in senescent mouse infarcts was followed by decreased myofibroblast density and markedly diminished collagen deposition in the scar. The healing defects in senescent animals were associated with enhanced dilative and hypertrophic remodeling and worse systolic dysfunction. Fibroblasts isolated from senescent mouse hearts showed a blunted response to TGF-beta1.

CONCLUSIONS

Although young mice exhibit a robust post-infarction inflammatory response and form dense collagenous scars, senescent mice show suppressed inflammation, delayed granulation tissue formation, and markedly reduced collagen deposition. These defects might contribute to adverse remodeling. These observations suggest that caution is necessary when attempting to therapeutically target the post-infarction inflammatory response in patients with reperfused MI. The injurious potential of inflammatory mediators might have been overstated, owing to extrapolation of experimental findings from young animals to older human patients.

The influence of age on health status outcomes after acute myocardial infarction

BACKGROUND

Older age is a risk factor for higher mortality after acute myocardial infarction (AMI), but the association with health status outcomes is largely unexplored.

METHODS

In a prospective cohort of 2498 patients in the PREMIER study, we compared health-related quality of life (HRQL) and burden of angina symptoms among survivors of AMI by age strata (age groups > or = 75, 65-74, 50-64, and 19-49 years) using the Seattle Angina Questionnaire. Multivariable analyses assessed the relationship between age and 1-year HRQL and angina burden, adjusting for differences in clinical characteristics, treatment, and baseline health status.

RESULTS

Older patients comprised a majority: 20.1% were > or = 75 years of age, 41.7% were 65 to 74 years of age, 20.7% were 50 to 64 years of age, and 17.4% were < 50 years of age. At 12 months, older patients had higher mortality (17.0% vs 8.7% vs 6.1% vs 3.2% for age groups > or = 75, 65-74, 50-64, 19-49; P < .001). Among survivors of AMI, increasing age was associated with less angina and better HRQL. By 12 months, older patients reported less angina (10.9% vs 12.7% vs 19.3% vs 23.4% for age groups > or = 75, 65-74, 50-64, 19-49; P < .0001) and better HRQL (scores 89.1 vs 88.1 vs 82.5 vs 80.0, respectively; P < .0001), which persisted after adjustment for baseline angina, HRQL, and other demographic, clinical, disease severity, and treatment differences.

CONCLUSIONS

Although older patients have higher mortality after AMI, those who survive experience fewer symptoms and better HRQL at 1 year than younger patients. Angina remains present in a number of patients across the spectrum of age, supporting strategies to systematically assess and treat symptoms after AMI.

Effects of ischemia and reperfusion on isolated ventricular myocytes from young adult and aged Fischer 344 rat hearts

This study examined the impact of age on contractile function, Ca2+homeostasis, and cell viability in isolated myocytes exposed to simulated ischemia and reperfusion. Ventricular myocytes were isolated from anesthetized young adult (3 mo) and aged (24 mo) male Fischer 344 rats. Cells were field-stimulated at 4 Hz (37°C), exposed to simulated ischemia, and reperfused with Tyrode solution. Cell shortening and intracellular Ca2+were measured simultaneously with an edge detector and fura-2. Cell viability was assessed by Trypan blue exclusion. Ischemia (20–45 min) depressed amplitudes of contraction equally in isolated myocytes from young adult and aged animals. The degree of postischemic contractile depression (stunning) was comparable in both groups. Ca2+transient amplitudes were depressed in early reperfusion in young adult and aged cells and then recovered to preischemic levels in both groups. Cell viability also declined equally in reperfusion in both groups. In short, some cellular responses to simulated ischemia and reperfusion were similar in both groups. Even so, aged myocytes exhibited a much greater and more prolonged accumulation of diastolic Ca2+in ischemia and in early reperfusion compared with myocytes from younger animals. In addition, the degree of mechanical alternans in ischemia increased significantly with age. The observation that there is an age-related increase in accumulation of diastolic Ca2+in ischemia and early reperfusion may account for the increased sensitivity to ischemia and reperfusion injury in the aging heart. The occurrence of mechanical alternans in ischemia may contribute to contractile dysfunction in ischemia in the aging heart.

Aging-induced alterations in gene transcripts and functional activity of mitochondrial oxidative phosphorylation complexes in the heart

Aging is associated with progressive decline in energetic reserves compromising cardiac performance and tolerance to injury. Although deviations in mitochondrial functions have been documented in senescent heart, the molecular bases for the decline in energy metabolism are only partially understood. Here, high-throughput transcription profiles of genes coding for mitochondrial proteins in ventricles from adult (6-months) and aged (24-months) rats were compared using microarrays. Out of 614 genes encoding for mitochondrial proteins, 94 were differentially expressed with 95% downregulated in the aged. The majority of changes affected genes coding for proteins involved in oxidative phosphorylation (39), substrate metabolism (14) and tricarboxylic acid cycle (6). Compared to adult, gene expression changes in aged hearts translated into a reduced mitochondrial functional capacity, with decreased NADH-dehydrogenase and F(0)F(1) ATPase complex activities and capacity for oxygen-utilization and ATP synthesis. Expression of genes coding for transcription co-activator factors involved in the regulation of mitochondrial metabolism and biogenesis were downregulated in aged ventricles without reduction in mitochondrial density. Thus, aging induces a selective decline in activities of oxidative phosphorylation complexes I and V within a broader transcriptional downregulation of mitochondrial genes, providing a substrate for reduced energetic efficiency associated with senescence.

Pleiotropic effects of cardiac drugs on healing post-MI. The good, bad, and ugly

Healing after myocardial infarction (MI) is a well-orchestrated time-dependent process that involves inflammation, tissue repair with extracellular collagen matrix (ECCM) deposition and scar formation, and remodeling of myocardial structure, matrix, vasculature, and function. Rapid early ECCM degradation followed by slow ECCM replacement and maturation during post-MI healing results in a prolonged window of enhanced vulnerability to adverse remodeling. Decreased ECCM results in adverse ventricular remodeling, dysfunction, and rupture. Inflammation, a critical factor in normal healing, if impaired results in adverse remodeling and rupture. Several therapeutic drugs prescribed after MI exert pleiotropic effects that suppress ECCM and inflammation during healing and may have good, bad, or ugly consequences. This article reviews the potential impact of pleiotropic effects of some prototypic cardiac drugs such as renin-angiotensin-aldosterone system (RAAS) inhibitors, statins, and thrombolytics during healing post-ST-segment-elevation MI (STEMI), with special focus on inflammation, ECCM and remodeling, and implications in the elderly.

Causes of death in patients with acute myocardial infarction treated with angiotensin-converting enzyme inhibitors: findings from the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto (GISSI)-3 trial

BACKGROUND

The causes of death occurring in clinical trials of myocardial infarction (MI) are scarcely reported in the literature. The present analysis is aimed to describe the inhospital causes of death in patients with acute MI stratified to angiotensin converting enzyme (ACE) inhibitor treatment/no treatment, as described in the GISSI-3 trial. Furthermore, the 5-year survival analysis of GISSI-3 patients is reported.

METHODS AND RESULTS

An independent committee assigned the definition of causes of death of GISSI-3 based on clinical and/or anatomical data. Univariate and multivariable analyses were performed to identify the predictors of early and late deaths. Kaplan-Meier mortality curves were used to describe the effects of ACE-I treatment on mortality on a median follow-up period of 56 months. Patients receiving lisinopril had fewer inhospital cardiac deaths than patients allocated to the no-lisinopril group (4.7% vs 5.3%, P = .052), corresponding to a 12% relative risk reduction. The risk of dying from cardiac rupture was reduced by 39% by lisinopril treatment. The improvement in survival associated with the lisinopril treatment was mainly due to a reduction in cardiac rupture, electromechanical dissociation, and pump failure occurring early (within 4 days) from the onset of MI symptoms. The beneficial effects of lisinopril observed at 6 weeks (8 fewer deaths per 1000 treated patients) were maintained up to nearly 5 years (10 fewer deaths per 1000).

CONCLUSIONS

Early administration of ACE inhibitors in unselected patients with acute MI should be considered standard therapy to reduce early deaths, specifically those due to cardiac rupture. The early beneficial effect persisted up to nearly 5 years.

Percutaneous coronary intervention in the elderly for myocardial infarction in the poststent era

BACKGROUND

Patients of > or =70 years of age and with acute coronary syndrome accumulate more risk factors with poor outcomes. Surgical revascularization is associated with increased mortality when compared with young population. The aim of this study was to communicate a single, small center experience, of percutaneous coronary intervention in the elderly in poststent era.

PATIENTS AND METHODS

Seventy-five consecutive patients, > or =70 years of age, with myocardial infarction (MI) at admission, between January, 2005 and November, 2006. We evaluate major and minor events during hospitalization.

RESULTS

Patients (64%) were male, 53.3% hypertension, 38.7% diabetes mellitus. Clinical presentation was: ST-segment elevation MI 53.3% and 5.3% with cardiogenic shock. Mean left ventricle ejection fraction was 48.5 +/- 18%. The procedure was successful in all the cases and culprit lesions received at least one stent in 93.4%. In-hospital major events were registered in 6.6% of cases: 3 (4%) death and 2 (2.6%) nonfatal MI; minor complications were registered in 5.2% of cases.

CONCLUSION

Percutaneous coronary intervention in patients >70 years of age during MI is feasible and safe, with low rates of complications.

Trends in Mortality from Acute Myocardial Infarction in the Coronary Care Unit

Introduction: The treatment and outcome of acute myocardial infarction (AMI) has evolved greatly over the past few decades. We compared the mortality and complication rates of patients with AMI admitted to the Coronary Care Unit (CCU) in 2002 to previously reported data. Materials and Methods: All data for AMI patients admitted to National Heart Centre CCU in 2002 were collected through the Singapore Cardiac Data Bank, including demographics, inhospital complications and mortality. These were compared to previous reports from the same institution in 1988, 1975 and 1967. Results: A total of 516 cases with AMI were identified. A higher proportion of patients were aged ≥70 years in 2002 (31.8%) compared to 1988 (25%), 1975 (11%) and 1967 (5.6%). Acute percutaneous transluminal coronary angioplasty (PTCA) was performed in 250 of 516 (48%) patients in 2002. The overall in-patient and age-standardised mortality was 14.7% and 10% respectively, compared to 20.6% and 17% respectively in 1988 (P = 0.06). For the 250 patients who underwent acute PTCA, overall mortality was 5.2% compared to 24% in those who did not (P <0.001). Common in-hospital complications included heart failure (38%), non-sustained ventricular tachycardia (8%), atrial fibrillation (8%) and complete heart block (6%). Age, heart failure, bundle branch block and sustained ventricular tachycardia were associated with higher mortality by univariate analysis. On multivariate analysis, older age, heart failure and the absence of percutaneous intervention were independently associated with higher mortality. Conclusion: In-hospital mortality for AMI patients admitted to the CCU declined from 1988 to 2002 despite a higher proportion of elderly patients. The introduction of new therapies including drugs and percutaneous intervention may have contributed to this decline. Key words: Primary percutaneous transluminal coronary angioplasty