GRACE risk score: Sex-based validity of in-hospital mortality prediction in Canadian patients with acute coronary syndrome.

BACKGROUND: Although there are sex differences in management and outcome of acute coronary syndromes (ACS), sex is not a component of Global Registry of Acute Coronary Events (GRACE) risk score (RS) for in-hospital mortality prediction. We sought to determine the prognostic utility of GRACE RS in men and women, and whether its predictive accuracy would be augmented through sex-based modification of its components. METHODS: Canadian men and women enrolled in GRACE and Canadian Registry of Acute Coronary Events were stratified as ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation ACS (NSTE-ACS). GRACE RS was calculated as per original model. Discrimination and calibration were evaluated using the c-statistic and Hosmer-Lemeshow goodness-of-fit test, respectively. Multivariable logistic regression was undertaken to assess potential interactions of sex with GRACE RS components. RESULTS: For the overall cohort (n=14,422), unadjusted in-hospital mortality rate was higher in women than men (4.5% vs. 3.0%, p<0.001). Overall, GRACE RS c-statistic and goodness-of-fit test p-value were 0.85 (95% CI 0.83-0.87) and 0.11, respectively. While the RS had excellent discrimination for all subgroups (c-statistics >0.80), discrimination was lower for women compared to men with STEMI [0.80 (0.75-0.84) vs. 0.86 (0.82-0.89), respectively, p<0.05]. The goodness-of-fit test showed good calibration for women (p=0.86), but suboptimal for men (p=0.031). No significant interaction was evident between sex and RS components (all p>0.25). CONCLUSIONS: The GRACE RS is a valid predictor of in-hospital mortality for both men and women with ACS. The lack of interaction between sex and RS components suggests that sex-based modification is not required.

In-hospital management and outcomes of acute coronary syndromes in relation to prior history of heart failure.

INTRODUCTION: The prognostic significance of prior heart failure in acute coronary syndromes has not been well studied. Accordingly, we evaluated the baseline characteristics, management patterns and clinical outcomes in patients with acute coronary syndromes who had prior heart failure. METHODS AND RESULTS: The study population consisted of acute coronary syndrome patients in the Global Registry of Acute Coronary Events, expanded Global Registry of Acute Coronary Events and Canadian Registry of Acute Coronary Events between 1999 and 2008. Of the 13,937 eligible patients (mean age 66±13 years, 33% female and 28.3% with ST-elevation myocardial infarction), 1498 (10.7%) patients had a history of heart failure. Those with prior heart failure tended to be older, female and had lower systolic blood pressure, higher Killip class and creatinine on presentation. Prior heart failure was also associated with significantly worse left ventricular systolic function and lower rates of cardiac catheterization and coronary revascularization. The group with previous heart failure had significantly higher rates of acute decompensated heart failure, cardiogenic shock, myocardial (re)infarction and mortality in hospital. In multivariable analysis, prior heart failure remained an independent predictor of in-hospital mortality (odds ratio 1.48, 95% confidence interval 1.08-2.03, p=0.015). CONCLUSIONS: Prior heart failure was associated with high risk features on presentation and adverse outcomes including higher adjusted in-hospital mortality in acute coronary syndrome patients. However, acute coronary syndrome patients with prior heart failure were less likely to receive evidence-based therapies, suggesting potential opportunities to target more intensive treatment to improve their outcome.

Prognostic significance of presenting blood pressure in non-ST-segment elevation acute coronary syndrome in relation to prior history of hypertension.

BACKGROUND: Hypertension is a well-established risk factor for cardiovascular disease, whereas low systolic blood pressure (SBP) is a powerful adverse prognosticator in acute coronary syndrome. However, it is unclear whether the prognostic significance of low SBP differs in patients with versus without prior history of hypertension. We sought to investigate the relationships between presenting SBP, prior hypertension, antihypertensive medication use, and outcomes in non-ST-segment elevation acute coronary syndrome (NSTEACS). METHODS: Using data from GRACE/GRACE(2) and CANRACE, we stratified 10,337 patients with NSTEACS from 1999 to 2008 into 2 groups: those with and those without prior diagnosis of hypertension. We performed multivariable logistic regression analysis to assess the prognostic significance of prior hypertension on in-hospital mortality and tested for the interactions between prior hypertension, antihypertensive medication use, and presenting SBP. RESULTS: Compared with patients without prior hypertension (n = 3,732), those with prior hypertension (n = 6,605) were older; more likely to be female; and more frequently had diabetes, previous myocardial infarction, heart failure, renal insufficiency, and higher Killip class and GRACE risk scores on presentation. Patients with prior hypertension were more likely to be on antihypertensive medications before admission, to present with higher SBP, and to have heart failure or cardiogenic shock in hospital (6.0% vs 10.1%; P < .001). In-hospital mortality was higher among patients presenting with lower SBP but did not differ between the groups with and without prior hypertension. In multivariable analysis, neither prior hypertension (adjusted odds ratio = 1.15, 95% CI 0.78-1.70, P = .48) nor the number of antihypertensive medications used (P for trend = .84) was independently associated with in-hospital mortality. In contrast, SBP was a strong independent predictor of in-hospital mortality (adjusted odds ratio = 1.21 per 10 mm Hg lower, 1.15-1.27, P < .001). There was no significant interaction between SBP and prior hypertension (P for interaction = .62) or pre-admission antihypertensive medication use (P for interaction = .46) with respect to in-hospital mortality. CONCLUSION: Low SBP on presentation, but not prior hypertension, was independently associated with in-hospital mortality in NSTEACS. The powerful prognostic value of SBP is similar regardless of a history of hypertension or pre-admission antihypertensive medication use.

Use and timing of coronary angiography and associated in-hospital outcomes in Canadian non-ST-segment elevation myocardial infarction patients: insights from the Canadian Global Registry of Acute Coronary Events.

BACKGROUND: Although an early invasive approach has become standard strategy for the management of non-ST-segment elevation myocardial infarction (NSTEMI), the frequency and timing in Canada is uncertain. METHODS: We examined the use and timing of coronary angiography, revascularization, and cardiovascular outcomes of NSTEMI patients: (1) admitted on weekdays vs weekends; and (2) stratified according to presentation risk level, in the Canadian Global Registry of Acute Coronary Events (GRACE)/Expanded GRACE (GRACE(2))/Canadian Registry of Acute Coronary Events (CANRACE) population. RESULTS: Of 6711 NSTEMI patients, 1956 (29.1%) were admitted on the weekend. The median (interquartile range) wait time for coronary angiography was 58 (32-106) and 70 (50-112) hours for weekday and weekend patients, respectively (P = 0.32). Compared with lower-intermediate risk, higher-risk patients were less likely to undergo angiography (44.7% vs 69.7% for weekdays and 45.2% vs 69.6% for weekends; both P < 0.0001) and waited longer for angiography (median 71 vs 61 hours; P < 0.0001). Weekend admission was independently associated with higher mortality (adjusted odds ratio [OR], 1.52; 95% confidence interval [CI], 1.15-2.01; P = 0.004), recurrent ischemia (adjusted OR, 1.16; 95% CI, 1.01-1.32; P = 0.03), and heart failure (adjusted OR, 1.28; 95% CI, 1.00-1.63; P = 0.048) but not with reinfarction. CONCLUSIONS: Median wait time for angiography in Canadian NSTEMI patients admitted on the weekend was not significantly longer than for those who presented on a weekday. Patients admitted on weekends had higher adjusted mortality and cardiovascular event rates. Higher-risk patients were less likely to undergo angiography and waited longer, with higher observed in-hospital event rates. Systematic, guideline-recommended risk stratification should be considered to ensure that optimal management strategies (eg, timely coronary angiography in higher-risk patients) are matched to level of risk.

Treatment and outcomes of non-ST elevation acute coronary syndromes in relation to burden of pre-existing vascular disease.

BACKGROUND: Patients with atherosclerotic disease in one territory often have disease in other vascular territories. However, the relationships between pre-existing vascular disease and the treatment and outcome of acute coronary syndrome (ACS), have not been well characterized. METHODS: The Canadian ACS2, Global Registry of Acute Coronary Events (GRACE/GRACE(2)), and Canadian Registry of Acute Coronary Events (CANRACE) were used to obtain data on 10,667 non-ST segment elevation acute coronary syndrome (NSTEACS) patients between 2002 and 2008. Multivariable analysis was used to examine the relationships between the number of vascular beds affected and both in-hospital coronary angiography and in-hospital mortality. The ACS2 registry (2002-2003) included physician-reported reasons for non-invasive management, which were stratified by vascular disease burden. RESULTS: Patients with more vascular disease had higher GRACE risk scores at presentation, but less frequently received antiplatelet agents and angiography. The most common reason in the ACS2 registry for patients who did not undergo angiography was "not high enough risk." There was an independent inverse relationship between the extent of vascular disease and in-hospital angiography. Patients with higher vascular disease burden had higher unadjusted in-hospital mortality. In multivariable analysis, patients with 1 vascular territory affected had the lowest and those with 3 vascular beds affected had the highest adjusted in-hospital mortality. In the ACS2 registry, patients with more extensive vascular disease had higher rates of 1-year mortality and death/re-infarction (both p for trend <0.001). CONCLUSIONS: NSTEACS patients with more vascular disease received less intensive treatment, with an associated worse outcome. This undertreatment might be partly mediated by physicians' underestimation of patient risk. More aggressive risk factor modification and intensive ACS therapies may improve the outcome of these high-risk patients.

The association between prior use of aspirin and/or warfarin and the in-hospital management and outcomes in patients presenting with acute coronary syndromes: insights from the Global Registry of Acute Coronary Events (GRACE).

BACKGROUND: The role of acetylsalicylic acid (ASA [aspirin]) and warfarin in secondary prevention after acute coronary syndromes (ACS) is well established. However, there are sparse data comparing the presentation and outcomes of patients who present with ACS while on ASA and/or warfarin therapy and those on neither. METHODS: Using data from the Canadian Global Registry of Acute Coronary Events (GRACE), we stratified 14,090 ACS patients into 4 groups according to prior use of antithrombotic therapies and compared in-hospital management and outcomes. RESULTS: Among 14,090 ACS patients, 7411 (52.6%) were not on prior ASA or warfarin therapy, 5724 (40.6%) were on ASA only, 593 (4.2%) were on warfarin only, and 362 (2.6%) were on both ASA and warfarin. ACS patients taking ASA and/or warfarin were older with more comorbidities than the patients on neither drug. Patients receiving prior warfarin only or ASA and warfarin were less likely to receive guideline-recommended therapies. Patients who were taking prior warfarin only had higher unadjusted rates of death, death and/or reinfarction (re-MI), congestive heart failure (CHF), and major bleeding as compared with patients on no prior therapy. Furthermore, patients who were taking ASA and warfarin had higher unadjusted rates of death and/or re-MI and CHF than patients on prior ASA only. CONCLUSIONS: ACS patients on prior warfarin are a high-risk population, yet they receive less guideline-recommended therapies and have higher unadjusted adverse event rates during their index hospitalization. With the increasing use of oral anticoagulants, clinical trials are needed to guide the optimal management of these ACS patients.

Reperfusion strategies and outcomes of ST-segment elevation myocardial infarction patients in Canada: observations from the Global Registry of Acute Coronary Events (GRACE) and the Canadian Registry of Acute Coronary Events (CANRACE).

BACKGROUND: We examine the clinical characteristics and outcomes of ST-elevation myocardial infarction (STEMI) patients receiving various reperfusion therapies in 2 contemporary Canadian registries. METHODS: Of 4045 STEMI patients, 2024 received reperfusion therapy and had complete data on invasive management. They were stratified by reperfusion strategy used: primary percutaneous coronary intervention (PCI) (n = 716); fibrinolysis with rescue PCI (n = 177); fibrinolysis with urgent/elective PCI (n = 210); and fibrinolysis without PCI (n = 921). Data were collected on clinical and laboratory findings, and outcomes. RESULTS: Compared with fibrinolytic-treated patients, patients treated with primary PCI were younger and had higher Killip class, had longer time to delivery of reperfusion therapy, and utilized more antiplatelet therapy but less heparin, ß-blockers and angiotensin-converting enzyme inhibitors. In-hospital death occurred in 2.7% of patients treated with primary PCI, 1.7% fibrinolysis-rescue PCI, 1.0% fibrinolysis-urgent/elective PCI, and 4.8% fibrinolysis-alone (P = 0.009); the rates of death/reinfarction were 3.9%, 4.0%, 4.3%, and 7.1% (P = 0.032), respectively. The rate of shock was highest in the primary PCI group. Rates of heart failure or major bleeding were similar in the 4 groups. In multivariable analysis, no PCI during hospitalization was associated with death and reinfarction (adjusted odds ratio = 1.66; 95% confidence interval, 1.03-2.70; P = 0.04). CONCLUSIONS: Clinical features, time to reperfusion, and medication utilization differed with respect to the reperfusion strategy. While low rates of re-infarction/death were observed, these complications occurred more frequently in those who did not undergo PCI during index hospitalization.

Temporal changes in the management and outcome of Canadian diabetic patients hospitalized for non-ST-elevation acute coronary syndromes.

BACKGROUND: There are limited data on the contemporary management and outcomes of non-ST-elevation acute coronary syndrome (NSTE-ACS) patients with diabetes in the "real world." We sought to evaluate (1) the temporal changes in the medical and invasive management and (2) in-hospital outcome of NSTE-ACS patients with and without diabetes. METHODS: We included Canadian patients hospitalized for NSTE-ACS enrolled in 4 consecutive, prospective, multicenter registries: Canadian ACS-I (n = 3259; 1999-2001), ACS-II (n = 1,956; 2002-2003), Global Registry of Acute Coronary Events (GRACE/GRACE2 [n = 7,561; 2004-2007]) and Canadian Registry of Acute Coronary Events (n = 1,326; 2008). Participants were stratified by the presence or absence of preexisting diabetes on admission. Temporal changes in patient management and outcomes were evaluated across the 4 registries. Multivariable analyses were performed to determine the independent prognostic significance of diabetes. RESULTS: Of the 14,102 NSTE-ACS patients, 4,046 (28.7%) had previously diagnosed diabetes. Patients with diabetes were older; were more likely to have prior cardiac history including myocardial infarction, revascularization, and heart failure; and had worse Killip class and higher GRACE risk score (all P < .001). Over time, there were significant increases in the use of in-hospital coronary angiography and revascularization. However, diabetic patients were less likely to undergo coronary angiography (52.5% vs 57%, P < .001) or revascularization (28.4% vs 33.4%, P < .001). The underuse of invasive procedures in diabetic patients was seen in all registries and was persistent over time. Overall, compared with the group without diabetes, diabetic patients had higher unadjusted rates of in-hospital mortality (3.0% vs 1.6%, P < .001). In multivariable analysis adjusting for components of the GRACE risk score, diabetes remained an independent predictor of in-hospital death (adjusted odds ratio 1.66, 95% CI 1.30-2.11, P < .001). CONCLUSIONS: Over the last decade, NSTE-ACS patients with diabetes continue to be treated more conservatively, despite evidence that they would derive similar or even greater benefits from aggressive treatment. This underutilization of evidence-based therapies among diabetic patients with NSTE-ACS in the "real world" may partly explain their worse outcome.

Use of clopidogrel post-coronary artery bypass surgery in canadian patients with acute coronary syndromes.

BACKGROUND: Randomized trials have established the efficacy of clopidogrel in acute coronary syndromes (ACS). The benefit of clopidogrel has also been observed in the subgroup of ACS patients who subsequently undergo coronary artery bypass surgery (CABG); however, this therapy is discontinued preoperatively and the frequency with which clopidogrel is restarted post-CABG is unknown. METHODS: We examined the pattern of clopidogrel use in the Canadian Global Registry of Acute Coronary Events (GRACE), GRACE2, and CANRACE (2003-2008) post-CABG ACS patients. We stratified the patients according to whether they underwent CABG during their index hospitalization for ACS and whether they were prescribed clopidogrel at discharge. RESULTS: Among those patients in whom clopidogrel status at discharge was known, 5904 (60%) of 9841 were discharged from hospital on clopidogrel. Use of clopidogrel at discharge was observed in 2222 (40.8%) of 5443 patients who were medically managed (ie, did not undergo percutaneous coronary intervention [PCI] or CABG) and in 3585 (90.1%) of 3980 patients who underwent in-hospital PCI. Overall, 455 (3.3%) of 13,776 patients underwent CABG during the index hospitalization; 255 (56%) patients were started on clopidogrel during the first 24 hours, and 66 of these patients (25.9%) were discharged on clopidogrel. In contrast, 5681 (61.3%) of the 9262 patients who did not undergo in-hospital CABG were discharged on clopidogrel. CONCLUSIONS: Although current guidelines recommend the use of clopidogrel post-CABG in patients with ACS, our observations suggest that only 1 in 4 or 5 Canadian patients are discharged on this therapy.

Has the ClOpidogrel and Metoprolol in Myocardial Infarction Trial (COMMIT) of early ß-blocker use in acute coronary syndromes impacted on clinical practice in Canada? Insights from the Global Registry of Acute Coronary Events (GRACE).

BACKGROUND: The COMMIT/CCS-2 trial, published in 2005, demonstrated no net benefit of early ß-blocker (BB) therapy in acute coronary syndromes (ACS). We sought to assess the short-term impact of this landmark trial by comparing the use of early BB therapy in patients with a broad spectrum of ACS before and after 2005. METHODS: Using data from the Global Registry of Acute Coronary Events and Canadian Registry of Acute Coronary Events, we compared the rates of BB use within the first 24 hours of presentation in the periods 1999 to 2005 and 2006 to 2008, after stratifying patients by the type of ACS (ST-segment elevation myocardial infarction [STEMI] and non-ST-segment elevation ACS [NSTEACS]) and clinical presentation. RESULTS: Of the 14,231 patients with ACS, 77.7% received BB therapy within 24 hours of presentation (78.5% and 77.4% in the STEMI and NSTEACS groups, respectively). The early use of BB declined in the STEMI group (80.3% to 76.7%, P = .005) but increased in the NSTEACS group (75.4% to 78.9%, P < .001) after 2005. Long-term BB use, higher systolic blood pressure, and higher heart rate were independent predictors of early BB use. Conversely, patients who were female, older, Killip class >1, and had cardiac arrest at presentation were less likely to receive early BB. Multivariable analysis showed a trend toward lower use of BB among patients with STEMI (adjusted odds ratio 0.76, 95% CI 0.57-1.00, P = .055) and a trend toward more frequent BB use among patients with NSTEACS (adjusted odds ratio 1.22, 95% CI 0.96-1.55, P = .11) after 2005. The temporal trends in the early use of BB differed between patients with STEMI and patients with NSTEACS (P for interaction with period <.001). CONCLUSIONS: Most patients with STEMI or NSTEACS were treated with early BB therapy. In accordance with the COMMMIT/CCS-2 trial, patients with lower systolic blood pressure and higher Killip class in the "real world" less frequently received early BB therapy. Since the publication of COMMIT/CCS-2, there has been no significant change in the use of BB in patients with STEMI or NSTEACS after controlling for their clinical characteristics.

Temporal trends in the use of invasive cardiac procedures for non-ST segment elevation acute coronary syndromes according to initial risk stratification.

BACKGROUND: Current guidelines support an early invasive strategy in the management of high-risk non-ST elevation acute coronary syndromes (NSTE-ACS). Although studies in the 1990s suggested that highrisk patients received less aggressive treatment, there are limited data on the contemporary management patterns of NSTE-ACS in Canada. OBJECTIVE: To examine the in-hospital use of coronary angiography and revascularization in relation to risk among less selected patients with NSTE-ACS. METHODS: Data from the prospective, multicentre Global Registry of Acute Coronary Events (main GRACE and expanded GRACE2) were used. Between June 1999 and September 2007, 7131 patients from across Canada with a final diagnosis of NSTE-ACS were included the study. The study population was stratified into low-, intermediate- and high-risk groups, based on their calculated GRACE risk score (a validated predictor of in-hospital mortality) and according to time of enrollment. RESULTS: While rates of in-hospital death and reinfarction were significantly (P<0.001) greater in higher-risk patients, the in-hospital use of cardiac catheterization in low- (64.7%), intermediate- (60.3%) and highrisk (42.3%) patients showed an inverse relationship (P<0.001). This trend persisted despite the increase in the overall rates of cardiac catheterization over time (47.9% in 1999 to 2003 versus 51.6% in 2004 to 2005 versus 63.8% in 2006 to 2007; P<0.001). After adjusting for confounders, intermediate-risk (adjusted OR 0.80 [95% CI 0.70 to 0.92], P=0.002) and high-risk (adjusted OR 0.38 [95% CI 0.29 to 0.48], P<0.001) patients remained less likely to undergo in-hospital cardiac catheterization. CONCLUSION: Despite the temporal increase in the use of invasive cardiac procedures, they remain paradoxically targeted toward low-risk patients with NSTE-ACS in contemporary practice. This treatment-risk paradox needs to be further addressed to maximize the benefits of invasive therapies in Canada.

Validation of the Global Registry of Acute Coronary Event (GRACE) risk score for in-hospital mortality in patients with acute coronary syndrome in Canada.

BACKGROUND: The Global Registry of Acute Coronary Event (GRACE) risk score was developed in a large multinational registry to predict in-hospital mortality across the broad spectrum of acute coronary syndromes (ACS). Because of the substantial regional variation and temporal changes in patient characteristics and management patterns, we sought to validate this risk score in a contemporary Canadian population with ACS. METHODS: The main GRACE and GRACE(2) registries are prospective, multicenter, observational studies of patients with ACS (June 1999 to December 2007). For each patient, we calculated the GRACE risk score and evaluated its discrimination and calibration by the c statistic and the Hosmer-Lemeshow goodness-of-fit test, respectively. To assess the impact of temporal changes in management on the GRACE risk score performance, we evaluated its discrimination and calibration after stratifying the study population into prespecified subgroups according to enrollment period, type of ACS, and whether the patient underwent coronary angiography or revascularization during index hospitalization. RESULTS: A total of 12,242 Canadian patients with ACS were included; the median GRACE risk score was 127 (25th and 75th percentiles were 103 and 157, respectively). Overall, the GRACE risk score demonstrated excellent discrimination (c statistic 0.84, 95% CI 0.82-0.86, P < .001) for in-hospital mortality. Similar results were seen in all the subgroups (all c statistics >/=0.8). However, calibration was suboptimal overall (Hosmer-Lemeshow P = .06) and in various subgroups. CONCLUSIONS: GRACE risk score is a valid and powerful predictor of adverse outcomes across the wide range of Canadian patients with ACS. Its excellent discrimination is maintained despite advances in management over time and is evident in all patient subgroups. However, the predicted probability of in-hospital mortality may require recalibration in the specific health care setting and with advancements in treatment.

Temporal trends and patterns of early clopidogrel use across the spectrum of acute coronary syndromes.

BACKGROUND: Randomized trials have established efficacy of clopidogrel in various types of acute coronary syndromes (ACS). The objective of this study was to examine the temporal trends and patterns of early clopidogrel use (within the first 24 hours of hospitalization) across the spectrum of patients with ACS in Canada. METHODS: Using the multinational, prospective GRACE (Global Registry of Acute Coronary Events) and GRACE(2), we identified 11,177 patients who were admitted for ACS from January 2003 to December 2007 in Canada. Demographic information, clinical features, and treatment were recorded. We examined the early use of clopidogrel over time and in relation to the type of ACS, clinical features on presentation, and the mode of reperfusion therapy. RESULTS: Of the 11,177 patients with ACS, 3,091 (27.7%) had ST-elevation myocardial infarction (STEMI), 5,194 (46.5%) had non-STEMI, and 2,892 (25.9%) had unstable angina; the rates of early clopidogrel administration were 63.0%, 66.6%, and 57.2%, respectively (P < .001). Overall, there was a significant increase in clopidogrel use over the period studied (P for trend < .001). In patients with non-ST-elevation ACS (non-STEMI and unstable angina), clopidogrel use was higher among those with positive cardiac biomarkers compared to those without (67.1% vs 59.8%, P < .001) but similar in the groups with and without ST deviation. There was an inverse relationship between GRACE risk score and rates of early clopidogrel administration. In patients with STEMI receiving fibrinolytic therapy, only 55.7% of patients <65 years old received clopidogrel compared with 47.0% and 42.6% of patients 65 to 74 and >75 years old, respectively (P for trend < .001). CONCLUSIONS: Although early use of clopidogrel therapy has increased over time across the spectrum of ACS, a significant proportion of eligible patients still do not receive this evidence-based therapy. There is a need to optimize the use of proven antiplatelet therapies to improve clinical outcome.