|
|
||||||||||
|
J Am Coll Cardiol, 2001; 38:41-48 © 2001 by the American College of Cardiology Foundation |


* Cardiology, University Hospital, Uppsala, Sweden
c Department of Thoracic Surgery, University Hospital, Uppsala, Sweden
Department of Cardiology, University Hospital, Linköping, Sweden
Manuscript received November 21, 2000; revised manuscript received March 21, 2001, accepted April 2, 2001.
Reprint requests and correspondence: Dr. Bo Lagerqvist, Department of Cardiology, Cardiothoracic Center, University Hospital, S-75 185 Uppsala, Sweden
bo.lagerqvist{at}card.uas.lul.se
| Abstract |
|---|
|
|
|---|
The Fragmin and fast Revascularization during InStability in Coronary artery disease (FRISC II) trial compared the effectiveness of an early invasive versus a noninvasive strategy in terms of the incidence of death and myocardial infarction (MI) in patients with unstable coronary artery disease (CAD).
OBJECTIVES
In this subanalysis, we sought to evaluate gender differences in the effect of these different strategies.
METHODS
The patients (749 women and 1,708 men) were randomized to early invasive or noninvasive strategies. Coronary angiography was performed within the first 7 days in 96% and 10% of the invasive and noninvasive groups, respectively, and revascularization was performed within the first 10 days in 71% and 9% of the invasive and noninvasive groups, respectively.
RESULTS
Women presenting with unstable CAD were older, but fewer had previous infarctions, left ventricular dysfunction and elevated troponin T levels. Women had fewer angiographic changes. There was no difference in MI or death at 12 months among women in the invasive and noninvasive groups (12.4% vs. 10.5%, respectively), in contrast to the favorable effect in the invasively treated group of men (9.6% vs. 15.8%, p < 0.001). In an interaction analysis, there was a different effect of the early invasive strategy for the two genders (p = 0.008).
CONCLUSIONS
Women with symptoms and/or signs of unstable CAD are older, but still have less severe CAD and a better prognosis compared with men. In contrast to its beneficial effect in men, an early invasive strategy did not reduce the risk of future events among women. Further research is warranted to identify the most appropriate treatment strategy in women with unstable CAD.
| ||||||||||||||||
The aim of the present analysis of the FRISC II is to compare men and women with unstable CAD in terms of their clinical variables at hospital admission, coronary anatomy, events during follow-up and outcome of the randomized invasive strategy compared with the noninvasive strategy.
| Methods |
|---|
|
|
|---|
Patients.
Patients were eligible for inclusion if they had symptoms of ischemia that were increasing or occurring at rest or if they had symptoms warranting suspicion of acute myocardial infarction (MI), with the last episode preceding the first dose of dalteparin or standard heparin by <48 h. Furthermore, myocardial ischemia had to be verified by electrocardiography (ST segment depression
0.1 mV or T-wave inversion
0.1 mV) or by elevation of biochemical markers: creatine kinase-MB isoenzyme (CK-MB) >6 µg/l, troponin T >0.10 µg/l, qualitative test for troponin T as positive or catalytic activity of CK, CK-B or CK-MB above the local decision limit for the diagnosis of MI. The details of exclusion criteria, the follow-up procedure and concomitant therapies are described in previous reports (15,16).
The study complied with the Declaration of Helsinki, and all local ethics committees approved the protocol. Written, informed consent was received from all patients.
Interventional strategies.
The invasive strategy required coronary angiography within a few days of enrollment, aiming for revascularization within seven days of starting open-label dalteparin (or standard heparin). Revascularization was recommended for all patients with
70% diameter obstruction in any artery supplying a significant proportion of the myocardium. If there were one or two target lesions, PCI was recommended, whereas CABG was preferred in patients with three-vessel or left main coronary artery (LMCA) disease.
The noninvasive strategy included coronary angiography in patients with refractory or recurrent symptoms, despite maximal medical treatment or severe ischemia on a predischarge symptom-limited exercise test (15). During long-term follow-up, invasive procedures were considered, regardless of randomized strategy, for all patients with incapacitating symptoms, recurrence of instability or MI.
In accordance with these guidelines, coronary angiography was performed within the first 7 days in 96% of the invasive group and in 10% of the noninvasive group, and revascularization was performed within the first 10 days in 71% and 9% of the invasive and noninvasive groups, respectively.
Statistical analysis.
Statistical analysis was performed on an intention-to-treat basis. Comparison of continuous variables was performed using the unpaired t test. The Mantel-Haenszel chi-square test was used to test the significance between the two strategy groups. Efficacy analyses were based on point estimates of events occurring from the start of open-label dalteparin treatment until 12 months and included only patients with an adjudicated event or with recorded absence of the evaluated event until at least day 335 of follow-up. The probability curves were constructed using the Kaplan-Meier method. Multivariate logistic regression analysis was performed to evaluate the effect of gender as an independent prognostic factor relating to the predefined combined end points of MI and death. In our model, we adjusted for the following clinical variables: age, diabetes, medically treated hypertension, smoking, history of angina pectoris for at least three months, previous MI, ST segment depression at hospital admission, troponin T
0.10 µg/l at admission and randomized long-term (three months) treatment with either low-molecular weight heparin (dalteparin) or placebo. When the model was used on the entire data (i.e., both strategy groups), then the randomized strategy (invasive or noninvasive) and the interaction variable of gender-strategy were included in the statistical model. In the invasive strategy group, a second multivariate analysis was performed when the presence or absence of angiographically significant stenosis was adjusted for. In all tests, p < 0.05 was considered statistically significant. The coordinating investigators performed data processing and statistical analyses using the SPSS version 10.0.5 statistical program for personal computers (SPSS, Inc., Chicago, Illinois).
| Results |
|---|
|
|
|---|
|
|
|
|
|
|
The outcomes are shown in Table 6. There was a trend toward a more severe outcome in the female group, but the difference was not statistically significant.
|
Outcomes of different types of coronary intervention in relation to gender (invasive group). Percutaneous coronary intervention was the first and, in most cases, the only intervention in 530 patients (43%; 133 women and 397 men) during follow-up. The corresponding number of patients who had CABG was 425 (35%; 101 women and 324 men). In 267 patients (22%; 114 women and 153 men), no intervention was performed.
There was no difference in outcome between the two genders if the first procedure was a PCI or if no intervention was performed. After CABG, there was a significantly worse outcome at 12 months in women compared with men (Table 7).
|
The event rates for women and men according to strategy group are presented in Figure 2A and B.
|
| Discussion |
|---|
|
|
|---|
Noninvasive strategy arm. Fewer interventions were made in women, because more women had normal coronary arteries or single-vessel disease. It is well known that patients without significant stenosis or single-vessel disease have a lower event rate compared with patients with significant two- or three-vessel disease or LMCA stenosis. In the present study, patients with no coronary stenosis had an excellent prognosis, with no deaths occurring during the 12-month follow-up period. Thus, the lower event rate seen in the noninvasive female group versus the noninvasive male group could be explained, to a large extent, by a greater proportion of patients with normal coronary angiograms among women. To illustrate this, the following calculation was performed. The rate of normal coronary angiograms and the prognosis in this group of patients were supposed to be the same in the noninvasive as in the invasive strategy group both for men and women. The presumed number of patients without coronary stenosis was excluded from the calculation. In the rest of the noninvasive group, the rate of death or MI within 12 months was calculated to 13.2% in women and 16.4% in men (p = 0.186, risk ratio 0.80, 95% confidence interval 0.58 to 1.11). Thus, after this calculated compensation for the lower prevalence of significant CAD among women, there was no actual gender difference in prognosis in the noninvasive strategy arm.
Invasive strategy arm. In the invasive group, there was no gender difference. One reason for this finding could be the higher procedure-related mortality in association with CABG among women. These findings are in accordance with the earlier randomized studies in which CABG-related mortality was higher among women (9,21). This is also in accordance with the Thrombolysis In Myocardial Infarction (TIMI IIIB) substudy in which the 42-day mortality rate tended to be higher in operated-on women (8.5%) than in operated-on men (2.2%) (p = 0.05) (18). However, subsequent larger scale studies have, to some degree, rejected these findings and have shown that the gender difference can be explained, to a large extent, by differences in comorbidities and other confounding factors (10,25). This explanation might also be the main reason for the outcome of CABG in the present trial, where women who underwent CABG were older and more often diabetic than men.
Thus, it is possible to speculate that the higher procedure-related mortality in women was due to the fact that CABG-treated women formed an especially high-risk group at surgery because of age, diabetes and more frequent previous MIs. It should also be observed that mortality in the CABG-treated men in the invasive arm was surprisingly low and not different from that in the PCI-treated cohort, despite considerable differences in risk factors between these groups. Thus, it cannot be excluded that the gender difference in CABG-related mortality in the invasive group was, to a large extent, a play of chance and that the overall mortality among the CABG-treated patients was the most representative procedure-related risk, regardless of gender.
Multivariate analysis. In the multivariate analysis, there was a clear gender-strategy interaction, even when taking into consideration confounding factors. The interaction analysis showed a different effect of the early invasive strategy for the two genders. Thus, in the present trial, women did not benefit from an early invasive strategy when they had unstable CAD, in contrast to men. This is partly attributable to a higher CABG-related mortality in women. However, subgroup analysis of the effect of the different types of intervention was not predefined in the FRISC II study. Furthermore, selection of the invasive procedure (PCI vs. CABG) was based on a "clinical decision" and not on randomization. This could have resulted in a concentration of high risk factors in women chosen for surgery. Consequently, it is important to be very cautious with the interpretation of these findings. The final evaluation of the efficacy of an early invasive strategy in women with unstable CAD will have to await the long-term follow-up of the present trial and the outcome of other ongoing trials on the same subject.
Study limitations. This study is based on a predefined substudy of the FRISC II invasive trial, analyzing gender differences. The numbers are too small and not powered enough to draw final conclusions, but they can be used to generate a hypothesis. As in the main study, all eligible patients were not included due to exclusion criteria, which is a limitation of all clinical trials. For definite knowledge, it is necessary to conduct a trial with enough power to detect differences in the early invasive treatment of women with unstable CAD.
Conclusions. We found that women in the FRISC II study had less advantage of an early invasive strategy, compared with men. The results emphasize that women with symptoms and/or signs of unstable CAD have less advanced atherosclerosis and a better prognosis, but often have important comorbidities associated with an increased invasive procedure-related risk. Therefore, despite demonstrating similar symptoms and signs of unstable CAD, women have less to gain from an early invasive strategy, at least in the short term. Thus, further research is warranted to identify women who are likely to benefit from or be harmed by an early invasive approach.
| Acknowledgments |
|---|
| Footnotes |
|---|
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
M. O'Donoghue, W. E. Boden, E. Braunwald, C. P. Cannon, T. C. Clayton, R. J. de Winter, K. A. A. Fox, B. Lagerqvist, P. A. McCullough, S. A. Murphy, et al. Early Invasive vs Conservative Treatment Strategies in Women and Men With Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction: A Meta-analysis JAMA, July 2, 2008; 300(1): 71 - 80. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. H. Han, J. H. Bae, D. R. Holmes Jr, R. J. Lennon, E. Eeckhout, G. W. Barsness, C. S. Rihal, and A. Lerman Sex differences in atheroma burden and endothelial function in patients with early coronary atherosclerosis Eur. Heart J., June 1, 2008; 29(11): 1359 - 1369. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. J. Shaw, R. E. Shaw, C. N. B. Merz, R. G. Brindis, L. W. Klein, B. Nallamothu, P. S. Douglas, R. J. Krone, C. R. McKay, P. C. Block, et al. Impact of Ethnicity and Gender Differences on Angiographic Coronary Artery Disease Prevalence and In-Hospital Mortality in the American College of Cardiology-National Cardiovascular Data Registry Circulation, April 8, 2008; 117(14): 1787 - 1801. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Holmvang and H. Mickley Review: Gender differences following percutaneous coronary intervention Therapeutic Advances in Cardiovascular Disease, April 1, 2008; 2(2): 109 - 113. [Abstract] [PDF] |
||||
![]() |
D. Radovanovic, P. Erne, P. Urban, O. Bertel, H. Rickli, J.-M. Gaspoz, and on behalf of the AMIS Plus Investigators Gender differences in management and outcomes in patients with acute coronary syndromes: results on 20 290 patients from the AMIS Plus Registry Heart, November 1, 2007; 93(11): 1369 - 1375. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Alfredsson, U. Stenestrand, L. Wallentin, and E. Swahn Gender differences in management and outcome in non-ST-elevation acute coronary syndrome Heart, November 1, 2007; 93(11): 1357 - 1362. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. M. Westerhout, M. S. Lauer, S. James, Y. Fu, L. Wallentin, P. W. Armstrong, and for the GUSTO IV ACS Investigators Electrocardiographic left ventricular hypertrophy in GUSTO IV ACS: an important risk marker of mortality in women Eur. Heart J., September 1, 2007; 28(17): 2064 - 2069. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Anderson, C. D. Adams, E. M. Antman, C. R. Bridges, R. M. Califf, D. E. Casey Jr, W. E. Chavey II, F. M. Fesmire, J. S. Hochman, T. N. Levin, et al. ACC/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 2002 Guidelines for the Management of Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction) Developed in Collaboration with the American College of Emergency Physicians, the Society for Cardiovascular Angiography and Interventions, and the Society of Thoracic Surgeons Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation and the Society for Academic Emergency Medicine J. Am. Coll. Cardiol., August 14, 2007; 50(7): e1 - e157. [Full Text] [PDF] |
||||
![]() |
L. Pilote, K. Dasgupta, V. Guru, K. H. Humphries, J. McGrath, C. Norris, D. Rabi, J. Tremblay, A. Alamian, T. Barnett, et al. A comprehensive view of sex-specific issues related to cardiovascular disease Can. Med. Assoc. J., March 13, 2007; 176(6): S1 - S44. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Milcent, B. Dormont, I. Durand-Zaleski, and P. G. Steg Gender Differences in Hospital Mortality and Use of Percutaneous Coronary Intervention in Acute Myocardial Infarction: Microsimulation Analysis of the 1999 Nationwide French Hospitals Database Circulation, February 20, 2007; 115(7): 833 - 839. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. M. Westerhout, Y. Fu, M. S. Lauer, S. James, P. W. Armstrong, E. Al-Hattab, R. M. Califf, M. L. Simoons, L. Wallentin, E. Boersma, et al. Short- and Long-Term Risk Stratification in Acute Coronary Syndromes: The Added Value of Quantitative ST-Segment Depression and Multiple Biomarkers J. Am. Coll. Cardiol., September 5, 2006; 48(5): 939 - 947. [Abstract] [Full Text] [PDF] |
||||
![]() |
G W Mikhail Coronary revascularisation in women Heart, May 1, 2006; 92(suppl_3): iii19 - iii23. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. J. Shaw, C. N. Bairey Merz, C. J. Pepine, S. E. Reis, V. Bittner, S. F. Kelsey, M. Olson, B. D. Johnson, S. Mankad, B. L. Sharaf, et al. Insights From the NHLBI-Sponsored Women's Ischemia Syndrome Evaluation (WISE) Study: Part I: Gender Differences in Traditional and Novel Risk Factors, Symptom Evaluation, and Gender-Optimized Diagnostic Strategies J. Am. Coll. Cardiol., February 7, 2006; 47(3_Suppl_S): S4 - S20. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. N. Bairey Merz, L. J. Shaw, S. E. Reis, V. Bittner, S. F. Kelsey, M. Olson, B. D. Johnson, C. J. Pepine, S. Mankad, B. L. Sharaf, et al. Insights From the NHLBI-Sponsored Women's Ischemia Syndrome Evaluation (WISE) Study: Part II: Gender Differences in Presentation, Diagnosis, and Outcome With Regard to Gender-Based Pathophysiology of Atherosclerosis and Macrovascular and Microvascular Coronary Disease J. Am. Coll. Cardiol., February 7, 2006; 47(3_Suppl_S): S21 - S29. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. J. Pepine, R. A. Kerensky, C. R. Lambert, K. M. Smith, G. O. von Mering, G. Sopko, and C. N. Bairey Merz Some Thoughts on the Vasculopathy of Women With Ischemic Heart Disease J. Am. Coll. Cardiol., February 7, 2006; 47(3_Suppl_S): S30 - S35. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. S. Anand, C. C. Xie, S. Mehta, M. G. Franzosi, C. Joyner, S. Chrolavicius, K. A.A. Fox, S. Yusuf, and for the CURE Investigators Differences in the Management and Prognosis of Women and Men Who Suffer From Acute Coronary Syndromes J. Am. Coll. Cardiol., November 15, 2005; 46(10): 1845 - 1851. [Abstract] [Full Text] [PDF] |
||||
![]() |
B Lagerqvist, E Diderholm, B Lindahl, S Husted, F Kontny, E Stahle, E Swahn, P Venge, A Siegbahn, and L Wallentin FRISC score for selection of patients for an early invasive treatment strategy in unstable coronary artery disease Heart, August 1, 2005; 91(8): 1047 - 1052. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Blomkalns, A. Y. Chen, J. S. Hochman, E. D. Peterson, K. Trynosky, D. B. Diercks, G. X. Brogan Jr, W. E. Boden, M. T. Roe, E. M. Ohman, et al. Gender disparities in the diagnosis and treatment of non-ST-segment elevation acute coronary syndromes: Large-scale observations from the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines) National Quality Improvement Initiative J. Am. Coll. Cardiol., March 15, 2005; 45(6): 832 - 837. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. F. Redberg Revascularization for everyone? Eur. Heart J., March 1, 2005; 26(5): 525 - 525. [Full Text] [PDF] |
||||
![]() |
A. J. Lansky, J. S. Hochman, P. A. Ward, G. S. Mintz, R. Fabunmi, P. B. Berger, G. New, C. L. Grines, C. G. Pietras, M. J. Kern, et al. Percutaneous Coronary Intervention and Adjunctive Pharmacotherapy in Women: A Statement for Healthcare Professionals From the American Heart Association Circulation, February 22, 2005; 111(7): 940 - 953. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. W. Armstrong and Y. Fu Assessing risk in FRISC Eur. Heart J., January 2, 2005; 26(2): 103 - 104. [Full Text] [PDF] |
||||
![]() |
R. A. Elkoustaf and W. E. Boden Is there a gender paradox in the early invasive strategy for non ST-segment elevation acute coronary syndromes? Eur. Heart J., September 2, 2004; 25(18): 1559 - 1561. [Full Text] [PDF] |
||||
![]() |
T.C. Clayton, S.J. Pocock, R.A. Henderson, P.A. Poole-Wilson, T.R.D. Shaw, R. Knight, and K.A.A. Fox Do men benefit more than women from an interventional strategy in patients with unstable angina or non-ST-elevation myocardial infarction? The impact of gender in the RITA 3 trial Eur. Heart J., September 2, 2004; 25(18): 1641 - 1650. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Rexius, G. Brandrup-Wognsen, A. Oden, and A. Jeppsson Gender and mortality risk on the waiting list for coronary artery bypass grafting Eur. J. Cardiothorac. Surg., September 1, 2004; 26(3): 521 - 527. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Nienaber, R. Fattori, R. H. Mehta, B. M. Richartz, A. Evangelista, M. Petzsch, J. V. Cooper, J. L. Januzzi, H. Ince, U. Sechtem, et al. Gender-Related Differences in Acute Aortic Dissection Circulation, June 22, 2004; 109(24): 3014 - 3021. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Moreno, A. Villate, J. Zamorano, C. Almeria, J.-A. Perez-Gonzalez, J.-L. Rodrigo, L. P. de Isla, L. Mataix, and C. Macaya Identifying patients without favourable long-term outcome among those with medically stabilized unstable angina and a negative dipyridamole stress echocardiogram Eur J Echocardiogr, June 1, 2004; 5(3): 205 - 211. [Abstract] [Full Text] [PDF] |
||||
![]() |
N Danchin Acute coronary syndromes: should women receive less antithrombotic medication than men? Heart, April 1, 2004; 90(4): 363 - 366. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. G. Nabel, H. P. Selker, R. M. Califf, J. G. Canto, J. J. Cao, P. Desvigne-Nikkens, R. J. Goldberg, J. R. Finnegan Jr, V. Vaccarino, R. Virmani, et al. Women's Ischemic Syndrome Evaluation: Current Status and Future Research Directions: Report of the National Heart, Lung and Blood Institute Workshop: October 2-4, 2002: Section 3: Diagnosis and Treatment of Acute Cardiac Ischemia: Gender Issues Circulation, February 17, 2004; 109 (6): e50 - e52. [Full Text] [PDF] |
||||
![]() |
S. D. Wiviott, C. P. Cannon, D. A. Morrow, S. A. Murphy, C. M. Gibson, C. H. McCabe, M. S. Sabatine, N. Rifai, R. P. Giugliano, P. M. DiBattiste, et al. Differential Expression of Cardiac Biomarkers by Gender in Patients With Unstable Angina/Non-ST-Elevation Myocardial Infarction: A TACTICS-TIMI 18 (Treat Angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction 18) Substudy Circulation, February 10, 2004; 109(5): 580 - 586. [Abstract] [Full Text] [PDF] |
||||
![]() |
W.-C. Chang, P. Kaul, C. M. Westerhout, M. M. Graham, Y. Fu, T. Chowdhury, and P. W. Armstrong Impact of Sex on Long-term Mortality From Acute Myocardial Infarction vs Unstable Angina Arch Intern Med, November 10, 2003; 163(20): 2476 - 2484. [Abstract] [Full Text] [PDF] |
||||