Effect of statin therapy before Q-wave myocardial infarction on myocardial perfusion

Impact of Prior Statin Therapy on In-Hospital Outcome of STEMI Patients Treated with Primary Percutaneous Coronary Intervention

Background: Prior statin therapy has a cardioprotective effect in patients undergoing elective or urgent percutaneous coronary intervention (PCI). However, data on patients with ST-elevation myocardial infarction (STEMI) undergoing primary PCI are still controversial. We retrospectively evaluated the effect of prior statin therapy on in-hospital clinical outcomes in consecutive STEMI patients undergoing primary PCI. Methods: A total of 1790 patients (mean age 67 ± 11 years, 1354 men) were included. At admission, all patients were interrogated about prior (>6 months) statin therapy. The primary endpoint of the study was the composite of in-hospital mortality, acute pulmonary edema, and cardiogenic shock in patients with or without prior statin therapy. Results: A total of 427 patients (24%) were on prior statin therapy. The incidence of the primary endpoint was similar in patients with or without prior statin therapy (15% vs. 16%; p = 0.38). However, at multivariate analysis, prior statin therapy was associated with a lower risk of the primary endpoint, after adjustment for major prognostic predictors (odds ratio 0.61 [95% CI 0.39−0.96]; p = 0.03). Conclusions: This study demonstrated that prior statin therapy is associated with a better in-hospital clinical outcome in patients with STEMI undergoing primary PCI compared to those without prior statin therapy.

Statins and myocardial infarction: Type, dose, and administration time: Does it matter?

Patients with ST-elevation myocardial infarction (STEMI) constitute a vulnerable group that demands the careful assessment and application of all the up-to-date clinical and experimental knowledge, with final aim, the improvement of their prognosis. Statins are an indispensable part of the primary and secondary prevention of coronary artery disease (CAD), not only due to their strong hypolipidemic effect, but also due to their numerous pleiotropic properties that play an important role in the treatment of CAD, especially when the more vulnerable group of STEMI patients is addressed. Nevertheless, there are still issues that require further discussion and clarification, such as the type of statin, the dose of the regimen, the administration time, and the treatment duration.

Myocardial Infarct Size in Patients on Long-Term Statin Therapy Undergoing Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

Statin pretreatment has been reported to have a cardioprotective effect in patients undergoing elective or urgent percutaneous coronary intervention (PCI). However, data on patients with ST-elevation myocardial infarction (STEMI) undergoing primary PCI are still controversial. We prospectively evaluated the effect of long-term statin therapy on infarct size (IS), myocardial salvage index (MSI), and microvascular obstruction (MVO) in consecutive patients with STEMI who underwent primary PCI. Two-hundred thirty patients with STEMI (mean age 61 ± 11 years, 183 men) who underwent primary PCI were evaluated with cardiac magnetic resonance (CMR) imaging during hospitalization (median 4 days after primary PCI). In all patients, we measured peak troponin I level, whereas IS, MSI, and MVO were determined by CMR. Fifty patients (22%) were on long-term statin therapy and showed a significantly lower troponin I peak value compared to patients without previous statins (54 ± 47 vs 88 ± 106 ng/ml; p = 0.02). At CMR evaluation, IS related to the index event was significantly smaller (12.5 ± 11.5 vs 18.5 ± 18.5 g, p = 0.05), and MSI was higher (0.68 ± 0.25 vs 0.52 ± 0.30; p <0.01) in patients with previous statin therapy. MVO was also less frequent (10% vs 20%; p = 0.14) in this group. At multivariate analysis, previous statin therapy remained significantly associated with IS and MSI (p = 0.05 and 0.02, respectively). In conclusion, this study suggests that long-term statin therapy before primary PCI in patients with STEMI is associated with smaller IS and higher MSI. Future studies are warranted to confirm these findings and to investigate potential clinical implications.

Effect of statin pretreatment on myocardial perfusion in patients undergoing primary percutaneous coronary intervention: a systematic review and meta-analysis

BACKGROUND

To achieve sufficient myocardial perfusion in ST-segment elevation myocardial infarction (STEMI) patients receiving primary percutaneous coronary intervention (PPCI), many adjunctive therapies have been proposed. Previous trials have reported variances in myocardial perfusion improvement for statin pretreatment, which made it inconvincible to confirm the beneficial effects of statins. Therefore, we performed a systematic review and meta-analysis to determine whether statin pretreatment was effective in improving myocardial perfusion.

HYPOTHESIS

Statin pretreatment could improve myocardial perfusion in STEMI patients undergoing PPCI.

METHODS

We searched the PubMed, Web of Knowledge, and the Cochrane Library databases for studies evaluating the impact of statin pretreatment on myocardial perfusion in STEMI patients receiving PPCI.

RESULTS

Twelve trials were finally included in our meta-analysis. There were no significant differences in patients' baseline characteristics between the statin pretreatment and control groups. Overall pooled analysis showed that patients in the statin pretreatment groups had significantly better epicardial coronary blood flow (measured by Thrombosis in Myocardial Infarction [TIMI] grade, odds ratio [OR]: 0.49, 95% confidence interval [CI]: 0.28 to 0.84; measured by corrected TIMI frame count, mean difference: -5.63; 95% CI: -9.66 to -1.6). A trend toward myocardial tissue level perfusion improvement was seen in the statin pretreatment arm rather than the control arm (measured by myocardial blush grade, OR: 0.74; 95% CI: 0.50 to 1.09).

CONCLUSIONS

This present meta-analysis suggests that statin pretreatment might be effective in improving myocardial perfusion in STEMI patients.

Early statin treatment prior to primary PCI for acute myocardial infarction: REPERATOR, a randomized placebo-controlled pilot trial

OBJECTIVE

The aim of this pilot study was to determine whether early atorvastatin treatment will reduce left ventricle (LV) remodeling, infarct size, and improve microvascular perfusion.

BACKGROUND

In animal studies, early statin therapy reduces reperfusion injury after a percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

METHODS

Forty-two consecutive patients (82% male, mean age 61.2 ± 9.8) who underwent a primary PCI for a first ST-elevated AMI were randomized for pretreatment with atorvastatin 80 mg (n = 20) or placebo (n = 22) and continued with the same dosage daily for 1 week. All patients received atorvastatin 80 mg once daily 7 days after primary PCI. The LV function and infarct size were measured by magnetic resonance imaging within 1 day, at 1 week, and 3 months follow up. The primary endpoint was the end-systolic volume index (ESVI) at 3 months. Secondary endpoints were global LV function measurements, myocardial infarct size, biochemical cardiac markers, TIMI flow, and ST-T elevation resolution.

RESULTS

ESVI 3 months after AMI was 25.1 mL/m(2) in the atorvastatin arm and 25.0 mL/m(2) in the placebo arm (P = 0.74). The differences in change from baseline to 3 months follow up in global LV function and myocardial infarct size did not differ between both treatment arms. Furthermore, biochemical markers, TIMI flow, and ST-T elevation resolution did not differ between atorvastatin and placebo arm.

CONCLUSIONS

In this pilot study, pretreatment with atorvastatin in an acute myocardial infarction does not result in an improved cardiac function, microvascular perfusion, or decreased myocardial infarct size.

Cardiogenic shock in ACS. Part 1: prediction, presentation and medical therapy

Ischemic cardiogenic shock is a complex, self-perpetuating pathological process that frequently causes death irrespective of medical therapy. Early definition of coronary anatomy is a pivotal step towards survival. Those destined to develop shock are likely to have three-vessel or left main stem disease with previously impaired left ventricular function. Early reperfusion of the occluded artery can limit infarct size, but ischemia-reperfusion injury or the 'no-reflow' phenomenon can preclude improvement in myocardial contractility. Emergence of shock depends upon the volume of ischemic myocardium, stroke volume, and peripheral vascular resistance. If cytokine release triggers the systemic inflammatory response, systemic vascular resistance falls and inadequate coronary perfusion pressure heralds the downward spiral. Survival depends on early recognition of shock, followed by aggressive targeted treatment of left, right, or biventricular failure. The goal is to prevent end-organ dysfunction and severe metabolic derangement by raising mean arterial pressure, which is achieved with inotropes and vasopressors, often at the expense of tachycardia, elevated myocardial oxygen consumption, and extended ischemia. The value of intra-aortic balloon counter-pulsation is now questioned in patients with advanced shock. When mean arterial pressure is <55 mmHg with serum lactate >11 mmol/l, death is likely and mechanical circulatory support becomes the only chance for survival.

Low-density lipoprotein receptor gene transfer in hypercholesterolemic mice improves cardiac function after myocardial infarction

Left ventricular (LV) function post-myocardial infarction (MI) is adversely influenced by hypercholesterolemia independent of the severity of coronary atherosclerosis. The objective of this study was to evaluate whether lipid lowering by adenoviral low-density lipoprotein (LDL) receptor (AdLDLr) gene transfer in C57BL/6 LDL receptor (LDLr)-deficient mice beneficially affects ventricular remodeling and cardiac function post-MI independent of effects on the coronary circulation. AdLDLr transfer reduced plasma cholesterol by 77% (P<0.0001). Survival 28 days post-MI was higher in AdLDLr-treated mice (95%) compared with control mice (80%) (P<0.05) (hazard ratio for mortality 0.26, 95% confidence interval 0.11–0.84). Infarct size was not significantly different at day 1 and day 7 but was reduced by 18% (P<0.05) at day 28 in AdLDLr MI mice compared with control MI mice. Cardiomyocyte hypertrophy and interstitial fibrosis were reduced and neovascularization was increased in AdLDLr MI mice. LDLr gene transfer had beneficial effects on endothelial progenitor cell (EPC) number and ex vivo EPC function. LV contractility and relaxation were better preserved in AdLDLr MI mice compared with control MI mice. In conclusion, lipid lowering in hypercholesterolemic mice exerts direct cardioprotective effects resulting in enhanced survival, reduced infarct size, decreased ventricular remodeling and better cardiac function.

Impact of chronic pre-treatment of statins on the level of systemic inflammation and myocardial perfusion in patients undergoing primary angioplasty

Statins have many favorable pleiotropic effects beyond their lipid-lowering properties. The aim of this study was to evaluate the impact of long-term statin pretreatment on the level of systemic inflammation and myocardial perfusion in patients with acute myocardial infarctions. This was a retrospective study of 1,617 patients with acute ST-segment elevation myocardial infarctions who underwent primary percutaneous coronary intervention <12 hours after the onset of symptoms. Angiographic no-reflow was defined as postprocedural Thrombolysis In Myocardial Infarction (TIMI) flow grade ≤2. Long-term statin pretreatment was significantly less common in the no-reflow group (6.2% vs 21%, p <0.001). The serum lipid profiles of the groups were similar (p >0.05 for all parameters). Baseline C-reactive protein levels (10 ± 8.2 vs 15 ± 14 mg/L, p <0.001) and the frequency of angiographic no-reflow (3.9% vs 14%, p <0.001) were significantly lower, and myocardial blush grade 3 was more common (50% vs 40%, p = 0.006) in the statin pretreatment group (n = 306). Moreover, the frequency of complete ST-segment resolution (>70%) (70% vs 59%, p <0.001) and the left ventricular ejection fraction were higher (49 ± 7.5% vs 46 ± 8.3%, p <0.001) and peak creatine kinase-MB was lower (186 ± 134 vs 241 ± 187 IU/L, p <0.001) in the statin-treated group. In conclusion, long-term statin pretreatment is associated with lower C-reactive protein levels on admission and better myocardial perfusion after primary percutaneous coronary intervention, leading to lower enzymatic infarct area and a more preserved left ventricular ejection fraction. This is a group effect independent of lipid-lowering properties.

Percutaneous coronary intervention, comorbidities, and mortality among emergency department-admitted ST-elevation myocardial infarction patients in Florida

BACKGROUND

Risk of mortality following an ST-elevation myocardial infarction (STEMI) can be significantly reduced by prompt percutaneous coronary intervention (PCI). National guidelines specify primary PCI as the preferred recommended treatment for STEMI. In this study, we examined same-day PCI as an independent predictor of in-hospital mortality, after adjustment for comorbidities, other patient factors, and hospital PCI-volume using unselected surveillance data from Florida.

METHODS

We analyzed hospital discharge data for adults, 18+ years old, with a primary diagnosis of STEMI who were admitted to PCI-capable hospitals through the emergency department during 2001-2005 (n = 43,849). Hierarchical (multilevel) logistic regression models were used for analysis.

RESULTS

Overall, 4,143 STEMI patients (9.4%) did not survive to hospital discharge. In late 2005, the in-hospital mortality rates were 1.9% for those who received same-day PCI versus 13.0% for those who did not. After adjustment for multiple patient factors, same-day PCI was a significant predictor of in-hospital survival with a strong protective effect (adjusted OR = 0.35, 95% CI 0.31-0.38 P < 0.0001). Restriction of the analysis to those patients who survived the first day of admission did not appreciably change this result (adjust OR = 0.37, 95% CI 0.33-0.42, P < 0.0001). Hospital PCI-volume did not significantly impact mortality risk.

CONCLUSIONS

Same-day PCI markedly reduced the risk of in-hospital mortality among STEMI patients after multivariate adjustment. Serious comorbidities and complications, older age, and female gender continued to predict elevated risk of mortality after control for treatment status. Our results provide additional evidence in support of national clinical recommendations and aggressive treatment of STEMI.

Coronary microembolization: from bedside to bench and back to bedside

Coronary microembolization from the erosion or rupture of a vulnerable atherosclerotic plaque occurs spontaneously in acute coronary syndromes and iatrogenically during percutaneous coronary interventions. Typical consequences of coronary microembolization are microinfarcts with an inflammatory response, contractile dysfunction, and reduced coronary reserve. Apart from transient elevations of creatine kinase and troponin, microemboli can be visualized by intracoronary Doppler and the resulting microinfarcts by late-enhancement nuclear magnetic resonance. Statins, antiplatelet agents, and coronary vasodilators protect against microembolization and microinfarction when started before percutaneous coronary interventions. Distal protection devices can retrieve atherothrombotic debris and prevent its embolization into the microcirculation, but their effect on clinical outcome has been disappointing so far, except for saphenous vein bypass grafts. Devices for aspiration of thrombi and thrombus-derived vasoconstrictor, thrombogenic, and inflammatory substances, however, reduce thrombus burden, improve perfusion, and provide protection in patients with acute myocardial infarction.

Effect of atorvastatin on platelet thromboxane A(2) synthesis in aspirin-treated patients with acute myocardial infarction

Inhibition of platelet thromboxane A(2) (TXA(2)) by aspirin is critical in patients with acute myocardial infarction (AMI), but some patients have persistent platelet TXA(2) production within 48 hours of the onset of AMI. Statins are known to reduce TXA(2) in aspirin-free patients with hypercholesterolemia. We hypothesized that treatment with aspirin plus atorvastatin could reduce persistent TXA(2) synthesis and aspirin resistance in patients with AMI. We evaluated platelet function in 184 aspirin-treated patients within 48 hours of the onset of AMI. Patients were divided into group A (treated with aspirin alone, n = 139) and group B (treated with aspirin plus atorvastatin, n = 45). We studied collagen-induced platelet TXA(2) synthesis, serotonin ((14)C-5HT) release and recruitment, and adenosine diphosphate-, arachidonic acid-, and collagen-induced platelet aggregation. Persistent TXA(2) synthesis was detected in 25% and 9% of groups A and B, respectively (p = 0.03). TXA(2), arachidonic acid-aggregation, and collagen-induced responses were significantly reduced in patients receiving dual treatment compared to those receiving aspirin monotherapy. Atorvastatin did not modify platelet reactivity in patients with efficiently blocked TXA(2) synthesis. These results strongly suggest a direct effect of the statin on platelet eicosanoid synthesis. This was confirmed in vitro by incubating washed aspirin-free and aspirin (1 muM)-treated platelets from normal subjects with 1 to 20 microM atorvastatin. Atorvastatin in vitro significantly reduced platelet TXA(2) synthesis and collagen-induced aggregation. In conclusion, atorvastatin combined with aspirin early in the onset of the acute event significantly reduced persistent TXA(2) and TXA(2)-dependent aspirin resistance. This could contribute to the clinical benefit of atorvastatin in patients with AMI.

Effect of previous treatment with statins on outcome of patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

Beyond lipid-lowering effects, statins have favorable effects on platelets, endothelial function, plaque stability, and inflammation. These "pleiotropic" effects could contribute to microvascular function preservation during ischemia. Data are limited about the impact of previous treatment with statins on outcomes of patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). Accordingly, the aim was to evaluate the effect of previous statin treatment on clinical outcomes of such patients. A total of 950 consecutive patients with STEMI treated with primary PCI who were included in our primary PCI registry from January 2001 to July 2007 were studied. Excluded were patients with cardiogenic shock. Patients were allocated into 2 groups: those who received previous statin treatment (n=327) and those who did not (n=623). Patients who received previous statin treatment were older and more likely to be women; have diabetes, hypertension, hyperlipidemia, renal insufficiency, and anemia; or have had a previous myocardial infarction. Procedural characteristics were similar between the 2 groups. Despite the higher risk profile, patients who received previous statin treatment had a lower 30-day mortality rate (1.5% vs 3.8%; p=0.05). However, at 6 months, mortality differences were no longer evident and patients who received previous statin therapy had a higher rate of target-vessel revascularization (12.4% vs 7.6%; p=0.02). Multivariate analysis showed that previous statin treatment was associated with an odds ratio of 0.4 (95% confidence interval 0.13 to 0.96, p=0.045) for 30-day mortality. In conclusion, the present study suggested that previous therapy with statins in patients with STEMI treated using primary PCI may be associated with reduced short-term mortality.

Relation between previous lipid-lowering therapy and infarct size (creatine kinase-MB level) in patients presenting with acute myocardial infarction

Animal experimental data have shown that lipid-lowering agents reduce myocardial infarct size. This association has not been well studied in humans. We compared infarct size in 10,548 patients in the GUSTO IIb and PURSUIT trials who were (n = 1,028) or were not (n = 9,520) on lipid-lowering therapy before an enrolling myocardial infarction (MI). Patients using lipid-lowering agents before their index MI had smaller infarcts than those who were not using these agents (median peak creatine kinase [CK]-MB 4.2 vs 5.2 times the upper limit of normal [ULN]; p <0.0001). Similarly, in an unadjusted model, patients on previous lipid-lowering therapy were less likely to have a peak CK-MB >3 times the ULN (620 of 1,028 [60.3%] vs 6,486 of 9,520 patients [68.1%]; p <0.001; relative risk 0.88, 95% confidence interval 0.84 to 0.93, p <0.0001). In a covariate- and propensity-adjusted multivariable model, the association between pretreatment with lipid-lowering agents and smaller infarct size persisted (relative risk for CK-MB >3 times the ULN 0.94, 95% confidence interval 0.88 to 0.99, p = 0.04). In conclusion, patients on lipid-lowering agents before an MI had significantly smaller infarcts. These findings suggest that lipid-lowering therapy may exert additional salutary effects in the setting of acute coronary syndromes.

Lipid management: considerations in acute coronary syndrome

Managing dyslipidemia is an important part of the primary and secondary prevention of coronary heart disease. Low-density lipoprotein cholesterol reduction remains the primary lipid goal. Patients who have experienced an acute coronary syndrome (ACS) are at very high risk of recurrent adverse cardiovascular events. A growing body of literature supports the concept that early and intensive treatment with statins after an ACS event decreases recurrent adverse cardiovascular events. We review available evidence pertaining to lipid alterations in ACS.