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Articles by L. J Shaw
Total Records ( 4 ) for L. J Shaw
  M Gulati , L. J Shaw , R. A Thisted , H. R Black , C. N Bairey Merz and M. F. Arnsdorf
 

Background— The definition of a normal heart rate (HR) response to exercise stress testing in women is poorly understood, given that most studies describing a normative response were predominately based on male data. Measures of an attenuated HR response (chronotropic incompetence) and age-predicted HR have not been validated in asymptomatic women. We investigated the association between HR response to exercise testing and age with prognosis in 5437 asymptomatic women.

Methods and Results— Participants underwent a symptom-limited maximal stress test in 1992. HR reserve (change in HR from rest to peak), chronotropic index, and age-predicted peak HR were calculated. Deaths were identified to December 31, 2008. Mean age at baseline was 52±11 years, with 549 deaths (10%) over 15.9±2.2 years. Mean peak HR was inversely associated with age; mean peak HR=206–0.88(age). After adjusting for exercise capacity and traditional cardiac risk factors, risk of death was reduced by 3% for every 1–beat-per-minute increase in peak HR, and by 2% for every 1–beat-per-minute increase in HR reserve (P<0.001). Inability to achieve 85% age-predicted HR was not an independent predictor of mortality, but being ≥1 SD below the mean predicted HR or a chronotropic index <0.80 based on the prediction model established by this cohort were independent predictors of mortality (P<0.001 and P=0.023, respectively).

Conclusions— Chronotropic incompetence is associated with an increased risk of death in asymptomatic women; however, the traditional male-based calculation overestimates the maximum HR for age in women. Sex-specific parameters of physiological HR response to exercise should be incorporated into clinical practice.

  L. J Shaw , J. K Min , J Narula , F Lin , C. N Bairey Merz , T. Q Callister and D. S. Berman
  Background—

Sex differences exist in the prevalence and severity of obstructive coronary artery disease (CAD). Limited data are available to explore sex differences in prognosis with coronary computed tomographic angiographic (CCTA) measurements of CAD including novel nonobstructive plaque extent.

Methods and Results—

A total of 1127 consecutive patients were clinically referred to 16-slice CCTA and followed for the occurrence of all-cause death. Time to death was calculated by univariable and multivariable Cox proportional hazard models. Four-year survival (92.1%) was similar by sex (P=0.52). Women more often had no coronary stenosis (54%) as compared with men (28%) (P<0.0001). Mortality worsened for both women (P<0.0001) and men (P=0.002) by the number of vessels with ≥50% stenosis. For women, overall mortality ranged from 3.5% for no CAD to 25.0% for women with 3-vessel plus left main obstructive CAD (P<0.0001). For men, overall mortality ranged from 2.7% for no CAD to 17.4% for males with 3-vessel plus left main obstructive CAD (P=0.002). Nonobstructive disease was prevalent in women (range, 24% to 66%) and men (range, 45% to 74%) ages 45 to ≥80 years. Nonobstructive CAD extent was a significant estimator of all-cause mortality when added to a model containing pretest CAD likelihood and obstructive CAD extent (P=0.039). For men, in a risk-adjusted model including pretest CAD likelihood and obstructive CAD, the number of nonobstructive lesions was not a significant estimator of mortality (P=0.9). For women, the relative hazard for mortality, in a multivariable model, was 1.3 per nonobstructive lesion (P=0.003), including pretest CAD likelihood and obstructive CAD as covariates. For women, risk-adjusted median mortality ranged from 2.9% to 10.9% for none to ≥4 nonobstructive lesions (P<0.0001).

Conclusions—

Based on our preliminary analyses, CCTA obstructive and nonobstructive CAD adds incremental value to clinical assessment for risk stratification. Moreover, the extent of nonobstructive CAD by CCTA predicts mortality in women but not in men and may be helpful to optimize therapeutic strategies for women.

  G.B. J Mancini , E. R Bates , D. J Maron , P Hartigan , M Dada , G Gosselin , W Kostuk , S. P Sedlis , L. J Shaw , D. S Berman , P. B Berger , J Spertus , K Mavromatis , M Knudtson , B. R Chaitman , R. A O'Rourke , W. S Weintraub , K Teo , W. E Boden and on behalf of the COURAGE Trial Investigators and Coordinators
 

Background— COURAGE compared outcomes in stable coronary patients randomized to optimal medical therapy plus percutaneous coronary intervention (PCI) versus optimal medical therapy alone.

Methods and Results— Angiographic data were analyzed by treatment arm, health care system (Veterans Administration, US non–Veterans Administration, Canada), and gender. Veterans Administration patients had higher prevalence of coronary artery bypass graft surgery and left ventricular ejection fraction ≤50%. Men had worse diameter stenosis of the most severe lesion, higher prevalence of prior coronary artery bypass graft surgery, lower left ventricular ejection fraction, and more 3-vessel disease that included a proximal left anterior descending lesion (P<0.0001 for all comparisons versus women). Failure to cross rate (3%) and visual angiographic success of stent procedures (97%) were similar to contemporary practice in the National Cardiovascular Data Registry. Quantitative angiographic PCI success was 93% (residual lesion <50% in-segment) and 82% (<20% in-stent), with only minor nonsignificant differences among health care systems and genders. Event rates were higher in patients with higher jeopardy scores and more severe vessel disease, but rates were similar irrespective of treatment strategy. Within the PCI plus optimal medical therapy arm, complete revascularization was associated with a trend toward lower rate of death or nonfatal myocardial infarction. Complete revascularization was similar between genders and among health care systems.

Conclusions— PCI success and completeness of revascularization did not differ significantly by health care system or gender and were similar to contemporary practice. Angiographic burden of disease affected overall event rates but not response to an initial strategy of PCI plus optimal medical therapy or optimal medical therapy alone.

  B. R Chaitman , P. M Hartigan , D. C Booth , K. K Teo , G. B. J Mancini , W. J Kostuk , J. A Spertus , D. J Maron , M Dada , R. A O'Rourke , W. S Weintraub , D. S Berman , L. J Shaw and W. E Boden
  Background—

The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial enrolled patients from 3 distinct healthcare systems (HCSs) in North America. The primary aim of this study was to determine whether there is a treatment difference in cardiovascular outcomes by HCS.

Methods and Results—

The study population included 968 patients from the US Department of Veterans Affairs (VA), 386 from the US non-VA, and 931 from Canada with different comorbidities and prognoses. The primary outcome was all-cause mortality or nonfatal myocardial infarction (MI) during the median 4.6-year follow-up. Baseline demographics were similar between percutaneous coronary intervention and optimal medical therapy treatment groups within each HCS. After follow-up, the primary end point of total mortality and nonfatal MI was not statistically significant between percutaneous coronary intervention and optimal medical therapy, regardless of HCS: VA, 22.3% versus 21.9% (hazard ratio, 1.05; 95% CI, 0.80–1.38; P=0.95); US non-VA, 15.8% versus 21.8% (hazard ratio, 0.70; 95% CI, 0.43–1.12; P=0.24); Canadian HCS, 17.3% versus 13.5% (hazard ratio, 1.30; 95% CI, 0.93–1.83; P=0.17). The interaction between HCSs and treatment was not statistically significant. Long-term mortality was significantly higher in the VA system as a result of significantly greater comorbidity and worse left ventricular function.

Conclusions—

In the COURAGE trial, addition of percutaneous coronary intervention to optimal medical therapy did not improve 5-year survival or reduce MI or other major adverse cardiovascular events regardless of whether patients were Canadian or American or US veterans or nonveterans. Outcome differences were largely explained by differences in baseline characteristics known to affect long-term prognosis.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00007657.

 
 
 
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