John K. French

Impact of thrombolysis, intra-aortic balloon pump counterpulsation, and their combination in cardiogenic shock complicating acute myocardial infarction : A report from the shock trial Registry

OBJECTIVES We sought to investigate the potential benefit of thrombolytic therapy (TT) and intra-aortic balloon pump counterpulsation (IABP) on in-hospital mortality rates of patients enrolled in a prospective, multi-center Registry of acute myocardial infarction (MI) complicated by cardiogenic shock (CS). BACKGROUND Retrospective studies suggest that patients suffering from CS due to MI have lower in-hospital mortality rates when IABP support is added to TT. This hypothesis has not heretofore been examined prospectively in a study devoted to CS. METHODS Of 1,190 patients enrolled at 36 participating centers, 884 patients had CS due to predominant left ventricular (LV) failure. Excluding 26 patients with IABP placed prior to shock onset and 2 patients with incomplete data, 856 patients were evaluated regarding TT and IABP utilization. Treatments, selected by local physicians, fell into four categories: no TT, no IABP (33%; n = 285); IABP only (33%; n = 279); TT only (15%; n = 132); and TT and IABP (19%; n = 160). RESULTS Patients in CS treated with TT had a lower in-hospital mortality than those who did not receive TT (54% vs. 64%, p = 0.005), and those selected for IABP had a lower in-hospital mortality than those who did not receive IABP (50% vs. 72%, p < 0.0001). Furthermore, there was a significant difference in in-hospital mortality among the four treatment groups: TT + IABP (47%), IABP only (52%), TT only (63%), no TT, no IABP (77%) (p < 0.0001). Patients receiving early IABP (< or = 6 h after thrombolytic therapy, n = 72) had in-hospital mortality similar to those with late IABP (53% vs. 41%, n = 64, respectively, p = 0.172). Revascularization rates differed among the four groups: no TT, no IABP (18%); IABP only (70%); TT only (20%); TT and IABP (68%, p < 0.0001); this influenced in-hospital mortality significantly (39% with revascularization vs. 78% without revascularization, p < 0.0001). CONCLUSIONS Treatment of patients in cardiogenic shock due to predominant LV failure with TT, IABP and revascularization by PTCA/CABG was associated with lower in-hospital mortality rates than standard medical therapy in this Registry. For hospitals without revascularization capability, a strategy of early TT and IABP followed by immediate transfer for PTCA or CABG may be appropriate. However, selection bias is evident and further investigation is required.

Increased Plasma Natriuretic Peptide Levels Reflect Symptom Onset in Aortic Stenosis

Background—The onset of symptoms is a critical point in the natural history of aortic stenosis and the cardinal indication for valve replacement. This study assessed the associations between natriuretic peptide levels, disease severity, and cardiac symptoms in aortic stenosis. Methods and Results—Seventy-four patients with isolated aortic stenosis underwent independent assessment of symptoms, transthoracic echocardiography, and measurement of plasma levels of atrial natriuretic peptide, brain natriuretic peptide (BNP), and N-BNP. Natriuretic peptide levels were also measured in 100 clinically normal control subjects. The aortic valve area was smaller in symptomatic patients (n=45) than in asymptomatic patients (n=29; mean, 0.71±0.23 cm2 and 0.99±0.31 cm2, respectively;P <0.0001). Plasma natriuretic peptide levels were higher in symptomatic patients than in asymptomatic patients (for N-BNP: median, 112 versus 33 pmol/L; interquartile range, 70 to 193 versus 16 to 58 pmol/L, respectively;P =0.0002). After adjustment for age, sex, serum creatinine, aortic valve area, and left ventricular ejection fraction, N-BNP levels were 1.74 times higher (95% confidence interval, 1.12 to 2.69) for symptomatic than asymptomatic patients with aortic stenosis (P =0.014). Natriuretic peptide levels increased with the New York Heart Association class (for N-BNP median values were 13, 34, 105, and 202 pmol/L for normal control subjects, class I, class II, and class III/IV patients, respectively; interquartile ranges for the same patients were 8 to 21, 16 to 58, 57 to 159, and 87 to 394 pmol/L;P <0.0001). Similar associations were observed for BNP and atrial natriuretic peptide. Conclusions—Plasma natriuretic peptide levels are elevated in symptomatic patients with aortic stenosis. Measurement of natriuretic peptides may complement clinical and echocardiographic evaluation of patients with aortic stenosis.

Intra-aortic balloon counterpulsation and infarct size in patients with acute anterior myocardial infarction without shock: the CRISP AMI randomized trial.

CONTEXT Intra-aortic balloon counterpulsation (IABC) is an adjunct to revascularization in patients with cardiogenic shock and reduces infarct size when placed prior to reperfusion in animal models. OBJECTIVE To determine if routine IABC placement prior to reperfusion in patients with anterior ST-segment elevation myocardial infarction (STEMI) without shock reduces myocardial infarct size. DESIGN, SETTING, AND PATIENTS An open, multicenter, randomized controlled trial, the Counterpulsation to Reduce Infarct Size Pre-PCI Acute Myocardial Infarction (CRISP AMI) included 337 patients with acute anterior STEMI but without cardiogenic shock at 30 sites in 9 countries from June 2009 through February 2011. INTERVENTION Initiation of IABC before primary percutaneous coronary intervention (PCI) and continuation for at least 12 hours (IABC plus PCI) vs primary PCI alone. MAIN OUTCOME MEASURES Infarct size expressed as a percentage of left ventricular (LV) mass and measured by cardiac magnetic resonance imaging performed 3 to 5 days after PCI. Secondary end points included all-cause death at 6 months and vascular complications and major bleeding at 30 days. Multiple imputations were performed for missing infarct size data. RESULTS The median time from first contact to first coronary device was 77 minutes (interquartile range, 53 to 114 minutes) for the IABC plus PCI group vs 68 minutes (interquartile range, 40 to 100 minutes) for the PCI alone group (P = .04). The mean infarct size was not significantly different between the patients in the IABC plus PCI group and in the PCI alone group (42.1% [95% CI, 38.7% to 45.6%] vs 37.5% [95% CI, 34.3% to 40.8%], respectively; difference of 4.6% [95% CI, -0.2% to 9.4%], P = .06; imputed difference of 4.5% [95% CI, -0.3% to 9.3%], P = .07) and in patients with proximal left anterior descending Thrombolysis in Myocardial Infarction flow scores of 0 or 1 (46.7% [95% CI, 42.8% to 50.6%] vs 42.3% [95% CI, 38.6% to 45.9%], respectively; difference of 4.4% [95% CI, -1.0% to 9.7%], P = .11; imputed difference of 4.8% [95% CI, -0.6% to 10.1%], P = .08). At 30 days, there were no significant differences between the IABC plus PCI group and the PCI alone group for major vascular complications (n = 7 [4.3%; 95% CI, 1.8% to 8.8%] vs n = 2 [1.1%; 95% CI, 0.1% to 4.0%], respectively; P = .09) and major bleeding or transfusions (n = 5 [3.1%; 95% CI, 1.0% to 7.1%] vs n = 3 [1.7%; 95% CI, 0.4% to 4.9%]; P = .49). By 6 months, 3 patients (1.9%; 95% CI, 0.6% to 5.7%) in the IABC plus PCI group and 9 patients (5.2%; 95% CI, 2.7% to 9.7%) in the PCI alone group had died (P = .12). CONCLUSION Among patients with acute anterior STEMI without shock, IABC plus primary PCI compared with PCI alone did not result in reduced infarct size. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00833612.

Randomized, Double-blind Comparison of Hirulog Versus Heparin in Patients Receiving Streptokinase and Aspirin for Acute Myocardial Infarction (HERO)

Background Thrombolytic therapy improves survival after myocardial infarction through reperfusion of the infarct-related artery. Thrombin generated during thrombolytic administration may reduce the efficacy of thrombolysis. A direct thrombin inhibitor may improve early patency rates. Methods and Results Four hundred twelve patients presenting within 12 hours with ST-segment elevation were given aspirin and streptokinase and randomized in a double-blind manner to receive up to 60 hours of either heparin (5000 U bolus followed by 1000 to 1200 U/h), low-dose hirulog (0.125 mg/kg bolus followed by 0.25 mg · kg−1 · h−1 for 12 hours then 0.125 mg · kg−1 · h−1), or high-dose hirulog (0.25 mg/kg bolus followed by 0.5 mg · kg−1 · h−1 for 12 hours then 0.25 mg · kg−1 · h−1). The primary outcome was Thrombolysis In Myocardial Infarction trial (TIMI) grade 3 flow of the infarct-related artery at 90 to 120 minutes. TIMI 3 flow was 35% (95% CI, 28% to 44%) with heparin, 46% (95% CI, 38% to 55%) with low-dose hirulog, a...

Bleeding complications with the P2Y12 receptor antagonists clopidogrel and ticagrelor in the PLATelet inhibition and patient Outcomes (PLATO) trial

AIMS More intense platelet-directed therapy for acute coronary syndrome (ACS) may increase bleeding risk. The aim of the current analysis was to determine the rate, clinical impact, and predictors of major and fatal bleeding complications in the PLATO study. METHODS AND RESULTS PLATO was a randomized, double-blind, active control international, phase 3 clinical trial in patients with acute ST elevation and non-ST-segment elevation ACS. A total of 18 624 patients were randomized to either ticagrelor, a non-thienopyridine, reversibly binding platelet P2Y(12) receptor antagonist, or clopidogrel in addition to aspirin. Patients randomized to ticagrelor and clopidogrel had similar rates of PLATO major bleeding (11.6 vs. 11.2%; P = 0.43), TIMI major bleeding (7.9 vs. 7.7%, P = 0.56) and GUSTO severe bleeding (2.9 vs. 3.1%, P = 0.22). Procedure-related bleeding rates were also similar. Non-CABG major bleeding (4.5 vs. 3.8%, P = 0.02) and non-procedure-related major bleeding (3.1 vs. 2.3%, P = 0.05) were more common in ticagrelor-treated patients, primarily after 30 days on treatment. Fatal bleeding and transfusion rates did not differ between groups. There were no significant interactions for major bleeding or combined minor plus major bleeding between treatment groups and age ≥75 years, weight <60 kg, region, chronic kidney disease, creatinine clearance <60 mL/min, aspirin dose >325 mg on the day of randomization, pre-randomization clopidogrel administration, or clopidogrel loading dose. CONCLUSION Ticagrelor compared with clopidogrel was associated with similar total major bleeding but increased non-CABG and non-procedure-related major bleeding, primarily after 30 days on study drug treatment. Fatal bleeding was low and did not differ between groups.

Clinical implications of the new definition of myocardial infarction

Myocardial infarction (MI) can be considered from several perspectives: clinical, electrocardiographic, biochemical, pathological, epidemiological, and imaging. The diagnosis of MI has psychological, social, and legal implications. MI is often used as a major end point in clinical trials. Historically, there has been tacit agreement as to the meaning of the term “myocardial infarction”. The World Health Organization definition, which has been widely used, requires the presence of two of the following three features: symptoms of myocardial ischaemia, elevation of cardiac marker (enzyme) concentrations in the blood, and a typical electrocardiographic pattern involving the development of Q waves or persistent T wave changes.w1 Using specific and highly sensitive immunoassays for myocardial proteins, such as cardiac troponins T and/or I, it is now possible to identify patients with small areas of myocardial necrosis. The emphasis on cardiac protein markers in the new American College of Cardiology/European Society of Cardiology (ACC/ESC) definition of MI, published in September 2000, has simplified the classification of MI.1 The new diagnostic criteria include a characteristic rise and fall in blood concentrations of cardiac troponins and/or creatine kinase (CK)-MB in the context of spontaneous ischaemic symptoms or coronary intervention (table 1).1 View this table: Table 1 The new ACC/ESC definition of myocardial infarction (MI)1 If it is accepted that any myocardial necrosis caused by ischaemia constitutes MI, many patients who were formerly diagnosed as having unstable angina pectoris will be now diagnosed as having had a small MI. For example, in a review of data from the Hennepin County Medical Centre (Minnesota, USA), the incidence of MI increased by 37% when the new definition of MI was applied.w2 However, the specificity of the new tests will reduce the number of false positive diagnoses of MI. Under the WHO classification, which was expanded for the monitoring trends and determinants …

Prospective evaluation of eligibility for thrombolytic therapy in acute myocardial infarction.

Abstract Objective: To determine the proportion of patients presenting with acute myocardial infarction who are eligible for thrombolytic therapy. Design: Cohort follow up study. Setting: The four coronary care units in Auckland, New Zealand. Subjects: All 3014 patients presenting to the units with suspected myocardial infarction in 1993. Main outcome measures: Eligibility for reperfusion with thrombolytic therapy (presentation within 12 hours of the onset of ischaemic chest pain with ST elevation >/=2 mm in leads V1-V3, ST elevation >/=1 mm in any other two contiguous leads, or new left bundle branch block); proportions of (a) patients eligible for reperfusion and (b) patients with contraindications to thrombolysis; death (including causes); definite myocardial infarction. Results: 948 patients had definite myocardial infarction, 124 probable myocardial infarction, and nine ST elevation but no infarction; 1274 patients had unstable angina and 659 chest pain of other causes. Of patients with definite or probable myocardial infarction, 576 (53.3%) were eligible for reperfusion, 39 had definite contraindications to thrombolysis (risk of bleeding). Hence 49.7% of patients (537/1081) were eligible for thrombolysis and 43.5% (470) received this treatment. Hospital mortality among patients eligible for reperfusion was 11.7% (55/470 cases) among those who received thrombolysis and 17.0% (18/106) among those who did not. Conclusions: On current criteria about half of patients admitted to coronary care units with definite or probable myocardial infarction are eligible for thrombolytic therapy. Few eligible patients have definite contraindications to thrombolytic therapy. Mortality for all community admissions for myocardial infarction remains high. Key messages Less than 10% of patients eligible for reperfusion have contraindications to thrombolysis The hospital mortality for all patients with acute myocardial infarction remains high (14%) Better treatments are required to reduce mortality in both reperfusion eligible and reperfusion ineligible patients

Four-year survival of patients with acute coronary syndromes without ST-segment elevation and prognostic significance of 0.5-mm ST-segment depression

We prospectively evaluated all patients admitted to our coronary care unit during 1993 with ischemic chest pain but without ST-segment elevation on the presenting electrocardiogram, and determined the influence of the extent of ST-segment depression, measured using calipers and blinded to the outcome, on 4-year survival. The presenting symptoms of 367 patients (mean age 64 years) were coded according to the Braunwald classification, 86% being in class IIIB (primary unstable angina with rest angina within 48 hours) and 7.4% in class IIIC (postinfarction angina). Thirty-two patients (8.6%) had myocardial infarction at presentation (defined as a creatine kinase level exceeding twice the reference range within 18 hours). During hospitalization 97% of patients received aspirin, 67% received intravenous heparin, 37% underwent angiography, and 35% underwent revascularization. The vital status of 99% of the patients was determined after a median of 52 months (interquartile range 48 to 55). At follow-up, 88% of patients were taking aspirin, 45% were taking beta blockers, and 50% had undergone revascularization. The survival rate was 70% in patients with > or = 0.5-mm ST-segment depression (53%, 77%, and 82% survival for > or = 2-, 1-, and 0.5-mm ST-segment depression, respectively; p <0.0001). Patients with a normal electrocardiogram had a greater survival rate (94%) than that of patients with 0.5-mm ST-segment depression (82%, p = 0.020), but not significantly different from that of patients with T-wave inversion (84%, p = NS). Independent predictors of mortality (odds ratio [95% confidence interval]) were: age in yearly increments (1.05 [1.03 to 1.06], p = 0.003), revascularization during follow-up (0.40 [0.29 to 0.56], p = 0.006), pulmonary edema (3.45 [2.19 to 5.45], p = 0.007), and ST-segment depression (1.37 [1.20 to 1.55], p = 0.015). Thus, ST-segment depression of > or = 0.5 mm predicts 4-year survival in patients with acute ischemic syndromes.

Angiographic findings and clinical correlates in Patients with cardiogenic shock complicating acute myocardial infarction : A report from the SHOCK Trial Registry

OBJECTIVES We sought to delineate the angiographic findings, clinical correlates and in-hospital outcomes in patients with cardiogenic shock (CS) complicating acute myocardial infarction. BACKGROUND Patients with CS complicating acute myocardial infarction carry a grave prognosis. Detailed angiographic findings in a large, prospectively identified cohort of patients with CS are currently lacking. METHODS We compared the clinical characteristics, angiographic findings, and in-hospital outcomes of 717 patients selected to undergo angiography and 442 not selected, overall and by shock etiology: left or right ventricular failure versus mechanical complications. RESULTS Patients who underwent angiography had lower baseline risk and a better hemodynamic profile than those who did not. Overall, 15.5% of the patients had significant left main lesions on angiography, and 53.4% had three-vessel disease, with higher rates of both for those with ventricular failure, compared with patients who had mechanical complications. Among patients who underwent angiography, those with ventricular failure had significantly lower in-hospital mortality than patients with mechanical complications (45.2% vs. 57.0%; p = 0.021). Importantly, for patients with ventricular failure, in-hospital mortality also correlated with disease severity: 35.0% for no or single-vessel disease versus 50.8% for three-vessel disease. Furthermore, mortality was associated with the culprit lesion location (78.6% in left main lesion, 69.7% in saphenous vein graft lesions, 42.4% in circumflex lesions, 42.3% in left anterior descending lesions, and 37.4% in right coronary artery lesions), and Thrombolysis In Myocardial Infarction (TIMI) flow grade (46.5% in TIMI 0/1, 49.4% in TIMI 2 and 26% in TIMI 3). CONCLUSIONS Patients who underwent angiographic study in the SHOCK Trial Registry had a more benign cardiac risk profile, more favorable hemodynamic findings and lower in-hospital mortality than those for whom angiograms were not obtained. Patients with CS caused by ventricular failure had more severe atherosclerosis, and a different distribution of culprit vessel involvement but lower in-hospital mortality, than those with mechanical complications. Overall in-hospital survival correlates with the extent of coronary artery obstructions, location of culprit lesion and baseline coronary TIMI flow grade.

Acute coronary syndrome care across Australia and New Zealand: the SNAPSHOT ACS study.

Objectives: To characterise management of suspected acute coronary syndrome (ACS) in Australia and New Zealand, and to assess the application of recommended therapies according to published guidelines.