Greg C Larsen

University of Minnesota Twin Cities, Minneapolis, MN, United States

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Publications (14)98.26 Total impact

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    Journal of the American College of Cardiology 12/2012; 60(23):2427–2463. · 14.09 Impact Factor
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    ABSTRACT: Accumulating evidence suggests that collaborative models of care enhance communication among primary care providers, improving quality of care and outcomes for patients with chronic conditions. We sought to determine whether a multifaceted intervention that used a collaborative care model and was directed through primary care providers would improve symptoms of angina, self-perceived health, and concordance with practice guidelines for managing chronic stable angina. We conducted a prospective trial, cluster randomized by provider, involving patients with symptomatic ischemic heart disease recruited from primary care clinics at 4 academically affiliated Department of Veterans Affairs health care systems. Primary end points were changes over 12 months in symptoms on the Seattle Angina Questionnaire, self-perceived health, and concordance with practice guidelines. In total, 183 primary care providers and 703 patients participated in the study. Providers accepted and implemented 91.6% of 701 recommendations made by collaborative care teams. Almost half were related to medications, including adjustments to β-blockers, long-acting nitrates, and statins. The intervention did not significantly improve symptoms of angina or self-perceived health, although end points favored collaborative care for 10 of 13 prespecified measures. While concordance with practice guidelines improved 4.5% more among patients receiving collaborative care than among those receiving usual care (P < .01), this was mainly because of increased use of diagnostic testing rather than increased use of recommended medications. A collaborative care intervention was well accepted by primary care providers and modestly improved receipt of guideline-concordant care but not symptoms or self-perceived health in patients with stable angina.
    Archives of internal medicine 09/2011; 171(16):1471-9. · 11.46 Impact Factor
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    ABSTRACT: Cardiac troponin levels help risk-stratify patients presenting with an acute coronary syndrome. Although cardiac troponin levels may be elevated in patients presenting with non-acute coronary syndrome conditions, specific diagnoses and long-term outcomes within that cohort are unclear. By using the Veterans Affairs centralized databases, we identified all hospitalized patients in 2006 who had a troponin assay obtained during their initial reference hospitalization. On the basis of the diagnostic codes of the International Classification of Diseases, 9th Revision, primary diagnoses were categorized as acute coronary syndrome or non-acute coronary syndrome conditions. Of a total of 21,668 patients with an elevated troponin level who were discharged from the hospital, 12,400 (57.2%) had a non-acute coronary syndrome condition. Among that cohort, the most common diagnostic category involved the cardiovascular system, and congestive heart failure (N=1661) and chronic coronary artery disease (N=1648) accounted for the major classifications. At 1 year after hospital discharge, mortality in patients with a non-acute coronary syndrome condition was 22.8% and was higher than in the acute coronary syndrome cohort (odds ratio 1.39; 95% confidence interval, 1.30-1.49). Despite the high prevalence of cardiovascular diseases in patients with a non-acute coronary syndrome diagnosis, use of cardiac imaging within 90 days of hospitalization was low compared with that in patients with acute coronary syndrome (odds ratio 0.25; 95% confidence interval, 0.23-0.27). Hospitalized patients with an elevated troponin level more often have a primary diagnosis that is not an acute coronary syndrome. Their long-term survival is poor and justifies novel diagnostic or therapeutic strategy-based studies to target the highest risk subsets before hospital discharge.
    The American journal of medicine 07/2011; 124(7):630-5. · 5.30 Impact Factor
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    ABSTRACT: Abdominal aortic operations have the highest perioperative cardiac risk. To test the impact of preoperative coronary artery revascularization (PR) in this high-risk subset, a post hoc analysis was performed in patients undergoing aortic surgery within the Coronary Artery Revascularization Prophylaxis (CARP) trial. The study cohort was a subset of 109 CARP patients with myocardial ischemia on nuclear imaging randomized to a strategy of PR (N = 52) or no PR (N = 57) before their scheduled abdominal aortic vascular operation. The clinical indications for vascular surgery were an expanding aneurysm (N = 62) or severe claudication (N = 47). The composite end-point of death and nonfatal myocardial infarction (MI) was determined by an intention-to-treat analysis following randomization. The median time (Interquartiles) from randomization to vascular surgery was 56 (40, 81) days in patients assigned to PR and 19 (10, 43) days in patients assigned to no PR (P < 0.001). At 2.7 years following randomization, the probability of remaining free of death and nonfatal MI was 0.65 with PR and 0.55 with no PR [unadjusted P = 0.08, odds ratio = 1.67, 95% confidence interval (0.93, 2.99)]. Using a Cox proportional hazard model, predictors of the composite of death and nonfatal MI (odds ratio; 95% confidence interval) were no PR (1.90; 1.06-3.43; P = 0.03) and anterior ischemia on preoperative imaging (1.79; 0.99-3.23; P = 0.07). In patients with an abnormal cardiac imaging before abdominal aortic vascular surgery, PR was associated with a reduced risk of death and nonfatal MI while anterior ischemia was an identifier of poor outcome independent of the revascularization status.
    Catheterization and Cardiovascular Interventions 01/2011; 77(1):134-41. · 2.51 Impact Factor
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    ABSTRACT: The natural history of coronary artery disease (CAD) after vascular surgery is poorly defined. The aim of this study was to determine the temporal change of coronary artery lesions requiring revascularization with a percutaneous coronary intervention (PCI) after elective vascular surgery and to determine the utility of preoperative biomarkers on predicting those patients at risk for new coronary lesions. The Coronary Artery Revascularization Prophylaxis Trial tested the long-term survival benefit of coronary artery revascularization before elective vascular surgery. Among randomized patients who subsequently required PCI after surgery, the stenosis of the culprit lesion from the follow-up angiogram was compared with the preoperative vessel stenosis at the identical site on the baseline angiogram. A total of 30 patients underwent PCI for progressive symptoms at a median of 11.5 (interquartiles: 4.5-18.5) months postsurgery. Of 30 patients, 16 (53%) had nonobstructive CAD preoperatively (group 1) with a stenosis that increased from 17 +/- 6% to 91 +/- 2% (P < 0.01) and 14 (47%) had severe CAD at the culprit site preoperatively (group 2), with a stenosis that increased 89 +/- 2% (P = 0.15). The only biomarker that was an identifier of early coronary artery lesion formation in group 1 compared with group 2 patients was a higher baseline homocysteine level (14.6 +/- 1.4 vs. 10.6 +/- 0.7 mg/dL; P = 0.02). Culprit coronary artery lesions requiring PCI after an elective vascular operation often arise from in-stent restenosis. Therapies that either stabilize existing plaques or prevent restenosis, particularly among patients with elevated homocysteine levels, have the greatest promise for improving postoperative outcomes.
    Annals of Vascular Surgery 07/2010; 24(5):596-601. · 0.99 Impact Factor
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    ABSTRACT: Objectifs L’histoire naturelle de la maladie coronarienne (CAD) après la chirurgie vasculaire reste mal définie. Le but de cette étude était de déterminer l’évolution des lésions de l’artère coronaire nécessitant une revascularisation par une intervention coronaire percutanée (PCI) après chirurgie vasculaire élective, et de déterminer l’utilité des biomarqueurs préopératoires sur la prédiction des patients à risque de nouvelles lésions coronaires. Méthodes L’étude Coronary Artery Revascularization Prophylaxis Trial a examiné l’avantage à long terme sur la survie de la revascularisation des artères coronaires avant chirurgie vasculaire élective. Parmi les patients randomisés qui ont plus tard eu besoin de PCI après chirurgie, la sténose de la lésion cible à l’angiographie de suivi a été comparée à la sténose préopératoire au même site sur l’angiographie de départ. Résultats Un total de 30 patients ont subi une PCI pour des symptômes progressifs sur une médiane de 11,5 mois (de 4,5 à 18,5) après chirurgie. Parmi les 30 patients, 16 (53%) avaient une CAD non obstructive en pré-opératoire (groupe 1) avec une sténose qui a augmenté de 17 ± 6% à 91 ± 2% (P < 0,01) et 14 (47%) avaient une CAD sévère au site cible en pré-opératoire (groupe 2), avec une sténose qui a augmenté de 89 ± 2% (P = 0,15). Le seul biomarqueur qui était un témoin de la formation précoce de lésion de l’artère coronaire dans le groupe 1 comparé aux patients du groupe 2 était un taux plus élevé d’homocystéine (14,6 ± 1,4 contre 10,6 ± 0,7 mg/dl ; P = 0,02). Conclusions Les lésions de l’artère coronaire symptomatique exigeant une PCI après une opération vasculaire élective se compliquent souvent de resténose. Les thérapies visant à stabiliser les plaques existantes ou à empêcher la resténose, en particulier chez les patients avec une homocystéinémie élevée, devraient permettre d’améliorer les résultats postopératoires.
    Annales de Chirurgie Vasculaire 07/2010; 24(5):651-656.
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    ABSTRACT: Background: Abdominal aortic operations have the highest perioperative cardiac risk. To test the impact of preoperative coronary artery revascularization (PR) in this high-risk subset, a post hoc analysis was performed in patients undergoing aortic surgery within the Coronary Artery Revascularization Prophylaxis (CARP) trial. Methods: The study cohort was a subset of 109 CARP patients with myocardial ischemia on nuclear imaging randomized to a strategy of PR (N = 52) or no PR (N = 57) before their scheduled abdominal aortic vascular operation. The clinical indications for vascular surgery were an expanding aneurysm (N = 62) or severe claudication (N = 47). The composite end-point of death and nonfatal myocardial infarction (MI) was determined by an intention-to-treat analysis following randomization. Results: The median time (Interquartiles) from randomization to vascular surgery was 56 (40, 81) days in patients assigned to PR and 19 (10, 43) days in patients assigned to no PR (P < 0.001). At 2.7 years following randomization, the probability of remaining free of death and nonfatal MI was 0.65 with PR and 0.55 with no PR [unadjusted P = 0.08, odds ratio = 1.67, 95% confidence interval (0.93, 2.99)]. Using a Cox proportional hazard model, predictors of the composite of death and nonfatal MI (odds ratio; 95% confidence interval) were no PR (1.90; 1.06–3.43; P = 0.03) and anterior ischemia on preoperative imaging (1.79; 0.99–3.23; P = 0.07). Conclusions: In patients with an abnormal cardiac imaging before abdominal aortic vascular surgery, PR was associated with a reduced risk of death and nonfatal MI while anterior ischemia was an identifier of poor outcome independent of the revascularization status. © 2010 Wiley-Liss, Inc.
    Catheterization and Cardiovascular Interventions 01/2010; · 2.51 Impact Factor
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    ABSTRACT: The Revised Cardiac Risk Index (RCRI) is useful for risk stratifying patients before noncardiac operations. Among patients with documented coronary artery disease who undergo vascular surgery, it is unclear whether preoperative revascularization reduces postoperative cardiac complications in high-risk subsets defined by the RCRI. The Coronary Artery Revascularization Prophylaxis Trial was a randomized, controlled trial that tested the long-term benefit of a preoperative coronary artery revascularization before elective vascular surgery. Using preoperative baseline characteristics to determine the RCRI, we tested the benefit of preoperative revascularization on death and nonfatal myocardial infarction in patients with multiple risks. Among 462 patients undergoing vascular surgery, there were 72 complications (15.6%) within 30 days postsurgery, including 15 deaths (3.2%) and 57 nonfatal myocardial infarctions (12.3%). The postoperative risk of death and nonfatal myocardial infarction after surgery increased according to the RCRI (odds ratio, 1.73; 95% CI, 1.26 to 2.38; P<0.001), with a rate of 1.6% in patients with no risk that increased to 23.4% in patients with > or =3 risks. Preoperative revascularization had no influence on the incidence of complications in any risk subset (odds ratio, 0.86; 95% CI, 0.50 to 1.49; P=0.60). Among those individuals with > or =2 risks who also demonstrated ischemia on a preoperative stress-imaging test (N=146), the incidence of events was 23% in patients with and without preoperative revascularization (P=0.95). The risk of death and nonfatal myocardial infarction is accurately predicted by the RCRI in patients undergoing vascular surgery but is not reduced in any high-risk subset of the RCRI with preoperative coronary artery revascularization.
    Circulation Cardiovascular Quality and Outcomes 03/2009; 2(2):73-7. · 5.66 Impact Factor
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    ABSTRACT: The Coronary Artery Revascularization Prophylaxis (CARP) study showed no survival benefit with preoperative coronary artery revascularization before elective vascular surgery. The generalizability of the trial results to all patients with multivessel coronary artery disease (CAD) has been questioned. The objective of this study was to determine the impact of prophylactic coronary revascularization on long-term survival in patients with multivessel CAD. Over a 4-year period, 1,048 patients underwent coronary angiography before vascular surgery during screening into the CARP trial. The cohort was composed of registry (n = 586) and randomized (n = 462) patients, and their survival was determined at 2.5 years after vascular surgery. High-risk coronary anatomy without previous bypass surgery included 2-vessel disease (n = 204 [19.5%]), 3-vessel disease (n = 130 [12.4%]), and left main coronary artery stenosis > or = 50% (n = 48 [4.6%]). By log-rank test, preoperative revascularization was associated with improved survival in patients with a left main coronary artery stenoses (0.84 vs 0.52, p <0.01) but not those with either 2-vessel (0.80 vs 0.79, p = 0.83) or 3-vessel (0.79 vs 0.71, p = 0.15) disease. In conclusion, unprotected left main coronary artery disease was present in 4.6% of patients who underwent coronary angiography before vascular surgery, and this was the only subset of patients showing a benefit with preoperative coronary artery revascularization.
    The American Journal of Cardiology 10/2008; 102(7):809-13. · 3.21 Impact Factor
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    ABSTRACT: Although patients in need of elective vascular surgery are often considered candidates for diagnostic coronary angiography, the safety of this invasive study has not been systematically studied in a large cohort of patients scheduled for an elective vascular operation. The goal of this sub-study of the Coronary Artery Revascularization Prophylaxis (CARP) trial was to assess the safety of coronary angiography in patients with peripheral vascular disease. The CARP trial tested the long-term benefit of coronary artery revascularization prior to elective vascular operations. Among those patients who underwent diagnostic coronary angiography during screening for the trial, the associated complications were determined at 24 hours following the diagnostic procedure. Over 5,000 patients were screened during a 4-year recruitment period at 18 major VA medical centers and the present cohort consists of 1,298 patients who underwent preoperative coronary angiography. Surgical indications for vascular surgery included an expanding aortic aneurysm (AAA) (n = 446; 34.4%) or arterial occlusive disease with either claudication (n = 457; 35.2%) or rest pain (n = 395; 30.4%). A total of 39 patients had a confirmed complication with a major complication identified in 17 patients (1.3%). Complication rates were higher in patients with arterial occlusive symptoms compared with expanding aneurysms (1.8% vs. 0.5%; P = 0.07) and were not dissimilar with femoral (2.8%) versus nonfemoral (4.7%) access sites (P = 0.42). Coronary angiography is safe in patients with peripheral arterial disease undergoing preoperative coronary angiography. The complication rate is higher in patients with symptoms of arterial occlusive disease.
    Journal of Interventional Cardiology 09/2008; 21(5):369-74. · 1.50 Impact Factor
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    ABSTRACT: It is unknown whether patients are at increased short-term risk for adverse events following clopidogrel cessation. To assess the rates of adverse events after stopping treatment with clopidogrel in a national sample of patients with acute coronary syndrome (ACS). Retrospective cohort study of 3137 patients with ACS discharged from 127 Veterans Affairs hospitals between October 1, 2003, and March 31, 2005, with posthospital treatment with clopidogrel. Rate of all-cause mortality or acute myocardial infarction (AMI) after stopping treatment with clopidogrel. Mean (SD) follow-up after stopping treatment with clopidogrel was 196 (152) days for medically treated patients with ACS without stents (n = 1568) and 203 (148) days for patients with ACS treated with percutaneous coronary intervention (PCI) (n = 1569). Among medically treated patients, mean (SD) duration of clopidogrel treatment was 278 [corrected] (169) [corrected] days and death or AMI occurred in 17.1% (n = 268) of patients, with 60.8% (n = 163) of events occurring during 0 to 90 days, 21.3% (n = 57) during 91 to 180 days, and 9.7% (n = 26) during 181 to 270 days after stopping treatment with clopidogrel. In multivariable analysis including adjustment for duration of clopidogrel treatment, the first 90-day interval after stopping treatment with clopidogrel was associated with a significantly higher risk of adverse events (incidence rate ratio [IRR], 1.98; 95% confidence interval [CI], 1.46-2.69 vs the interval of 91-180 days). Similarly, among PCI-treated patients with ACS, mean (SD) duration of clopidogrel treatment was 302 [corrected] (151) [corrected] days and death or AMI occurred in 7.9% (n = 124) of patients, with 58.9% (n = 73) of events occurring during 0 to 90 days, 23.4% (n = 29) during 91 to 180 days, and 6.5% (n = 8) during 181 to 270 days after stopping clopidogrel treatment. In multivariable analysis including adjustment for duration of clopidogrel treatment, the first 90-day interval after stopping clopidogrel treatment was associated with a significantly higher risk of adverse events (IRR, 1.82; 95% CI, 1.17-2.83). We observed a clustering of adverse events in the initial 90 days after stopping clopidogrel among both medically treated and PCI-treated patients with ACS, supporting the possibility of a clopidogrel rebound effect. Additional studies are needed to confirm the clustering of events after stopping clopidogrel, including associations with cardiovascular mortality and reasons for stopping clopidogrel, as well as to determine the mechanism of this phenomenon, and to identify strategies to reduce early events after clopidogrel cessation.
    JAMA The Journal of the American Medical Association 03/2008; 299(5):532-9. · 29.98 Impact Factor
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    ABSTRACT: The predictors and outcomes of patients with a peri-operative elevation in cardiac troponin I above the 99th percentile of normal following an elective vascular operation have not been studied in a homogeneous cohort with documented coronary artery disease. The Coronary Artery Revascularization Prophylaxis (CARP) trial was a randomized trial that tested the benefit of coronary artery revascularization prior to vascular surgery. Among 377 randomized patients, core lab samples for peak cardiac troponin I concentrations were monitored following the vascular operation and the blinded results were correlated with outcomes. A peri-operative myocardial infarction (MI), defined by an increase in cardiac troponin I greater than the 99th percentile reference (> or =0.1 microg/L), occurred in 100 patients (26.5%) and the incidence was not dissimilar in patients with and without pre-operative coronary revascularization (24.2 vs. 28.6%; P = 0.32). By logistic regression analysis, predictors of MI (odds risk; 95%CI; P-value) were age >70 (1.84; 1.14-2.98; P = 0.01), abdominal aortic surgery (1.82; 1.09-3.03; P = 0.02), diabetes (1.86; 1.11-3.11; P = 0.02), angina (1.67; 1.03-2.64; P = 0.04), and baseline STT abnormalities (1.62; 1.00-2.6; P = 0.05). At 2.5 years post-surgery, the probability of survival in patients with and without the MI was 0.73 and 0.84, respectively (P = 0.03, log-rank test). Using a Cox proportional hazards regression analysis, a peri-operative MI in diabetic patients was a strong predictor of long-term mortality (hazards ratio: 2.43; 95% CI: 1.31-4.48; P < 0.01). Among patients with coronary artery disease who undergo vascular surgery, a peri-operative elevation in cardiac troponin levels is common and in combination with diabetes, is a strong predictor of long-term mortality. These data support the utility of cardiac troponins as a means of stratifying high-risk patients following vascular operations.
    European Heart Journal 02/2008; 29(3):394-401. · 14.72 Impact Factor
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    ABSTRACT: Preoperative cardiac risks and clinical indications for vascular surgery are both important determinants of outcome following a vascular operation. Using the nonrandomized cohort from the Coronary Artery Revascularization Prophylaxis (CARP) Trial, we analyzed the predictors of outcome based on the presenting vascular problem and prevalence of comorbid conditions and cardiac risks. Between March 1, 1999 and February 28, 2003, 4414 patients were ineligible for randomization in the CARP Trial and their survival was retrieved through the BIRLS system (the Department of Veterans Affairs Beneficiary Identification and Records Locator Subsystem). Surgical indications were either an abdominal aortic aneurysm (N = 1598) or lower extremity ischemia for claudication (N = 1116), rest pain (N = 670), or tissue loss (N = 1030). Patients were screened for major cardiac risks that included a history of angina, congestive heart failure, myocardial infarction, ventricular arrhythmias, pathological q-waves, and diabetes. The absence of multiple cardiac risks, as the sole reason for exclusion from randomization, occurred in 2314 (52.4%) screened patients and their probability of survival at 2.5-year post-surgery was 0.88. This was better than the survival of the remaining excluded patients (N = 2100), which was 0.75 (P < .0001) and the randomized cohort (N = 462), which was 0.80 (P < .0001). By Cox regression analysis, urgent surgery, congestive heart failure, ventricular arrhythmias and creatinine >3.5 mg/dL were significantly associated with long-term postoperative mortality. Patients without multiple cardiac risks or comorbid conditions have a good outcome following elective vascular surgery. Urgent surgery, creatinine >3.5 mg/dL, congestive heart failure, and ventricular arrhythmias are identifiers of a poor long-term outcome and may justify aggressive strategies for risk-stratification in the postoperative period.
    Journal of Vascular Surgery 11/2007; 46(4):694-700. · 2.88 Impact Factor
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    ABSTRACT: Among patients in need of coronary revascularization before an elective vascular operation, the value of coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) in preventing perioperative myocardial infarctions is uncertain. We hypothesized that more complete revascularization would improve outcomes after vascular surgery. In this Veterans Affairs Cooperative trial involving 18 medical centers, 222 patients underwent elective vascular surgery after coronary revascularization. The mode of coronary revascularization was selected at each site by the local investigators (CABG in 91 patients and PCI in 131 patients). The vascular surgical indications were similar in both groups. There were 2 deaths in the CABG group (2.2%) and 5 deaths in the PCI group (3.8%; p = 0.497) after the vascular procedure. There were fewer perioperative myocardial infarctions after the vascular operation in CABG patients (6.6%) than in PCI patients (16.8%; p = 0.024), despite more diseased vessels in the CABG group (3.0 +/- 1.3 versus 2.2 +/- 1.4, respectively; p < 0.001). The completeness of revascularization (defined as the number of coronary artery vessels revascularized relative to the total number of vessels with a stenosis > or = 70%) in patients in the CABG and PCI groups was 117% +/- 63% and 81% +/- 57%, respectively (p < 0.001). Hospital length of stay in CABG versus PCI patients was 6 (4, 8) and 7 (4, 10) days, respectively (p = 0.078). Among patients receiving multivessel coronary artery revascularization as prophylaxis for elective vascular surgery, patients having a CABG had fewer myocardial infarctions and tended to spend less time in the hospital after the vascular operation than patients having a PCI. More complete revascularization accounted for the intergroup differences.
    The Annals of thoracic surgery 09/2006; 82(3):795-800; discussion 800-1. · 3.45 Impact Factor

Publication Stats

292 Citations
98.26 Total Impact Points

Institutions

  • 2011
    • University of Minnesota Twin Cities
      • Department of Medicine
      Minneapolis, MN, United States
  • 2006–2011
    • Portland VA Medical Center
      Portland, Oregon, United States
  • 2006–2009
    • University of Minnesota Duluth
      • Medical School
      Duluth, Minnesota, United States
  • 2008
    • Oregon Health and Science University
      Portland, Oregon, United States