Charles A Herzog

Hennepin County Medical Center, Minneapolis, Minnesota, United States

Are you Charles A Herzog?

Claim your profile

Publications (137)999.28 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Calciphylaxis, a rare disease seen in chronic dialysis patients, is associated with significant morbidity and mortality. As is the case with other rare diseases, the precise epidemiology of calciphylaxis remains unknown. Absence of a unique International Classification of Diseases (ICD) code impedes its identification in large administrative databases such as the United States Renal Data System (USRDS) and hinders patient-oriented research. This study was designed to develop an algorithm to accurately identify cases of calciphylaxis and to examine its incidence and mortality.
    Journal of general internal medicine. 07/2014;
  • JACC. Cardiovascular imaging 02/2014; 7(2):206-7. · 14.29 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BP variability (BPV) is an important predictor of outcomes in the general population, but its association with clinical outcomes in hemodialysis patients is not clear. We identified 11,291 patients starting dialysis in 2003-2008 and followed them through December 31, 2008 (median=22 months). Predialysis systolic BPV was assessed over monthly intervals. Outcomes included factors associated with BPV, mortality (all-cause and cardiovascular), and first cardiovascular event (cardiovascular death or hospitalization). Patients' mean age was 62 years, 55% of patients were men, and 58% of patients were white. Modifiable factors associated with higher BPV included obesity, higher calcium-phosphate product levels, and lower hemoglobin concentration; factors associated with lower BPV included greater fluid removal, achievement of prescribed dry weight during dialysis, higher hemoglobin concentration, and antihypertensive regimens without β-blockers or renin-angiotensin system blocking agents. In total, 3200 deaths occurred, including 1592 cardiovascular deaths. After adjustment for demographics, comorbidities, and clinical factors, higher predialysis BPV was associated with increased risk of all-cause mortality (hazard ratio [HR], 1.18; 95% confidence interval [95% CI] per 1 SD increase in BPV, 1.13 to 1.22), cardiovascular mortality (HR, 1.18; 95% CI, 1.12 to 1.24), and first cardiovascular event (HR, 1.11; 95% CI, 1.07 to 1.15). Results were similar when BPV was categorized in tertiles and patients were stratified by baseline systolic BP. In summary, predialysis systolic BPV is an important, potentially modifiable risk factor for death and cardiovascular outcomes in incident hemodialysis patients. Studies of BP management in dialysis patients should focus on both absolute BP and BPV.
    Journal of the American Society of Nephrology 01/2014; · 8.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The plasma pool of potassium is a partial reflection of the overall body, transient cellular shifts, and potassium elimination regulated by the kidneys. Potassium concentrations elevating above the upper limit of normal (> 5.0 mEq/L) have become more common in cardiovascular practice due to the growing population of patients with chronic kidney disease and the broad applications of drugs that modulate potassium excretion by either reducing production of angiotensin II (angiotensin-converting enzyme inhibitors, direct renin inhibitors, beta-adrenergic receptor antagonists), blocking angiotensin II receptors (angiotensin receptor blockers), or antagonizing the action of aldosterone on mineralocorticoid receptors (mineralocorticoid receptor antagonists). In addition, acute kidney injury, critical illness, crush injuries, and massive red blood cell transfusions can result in hyperkalemia. Progressively more severe elevations in potassium are responsible for abnormalities in cardiac depolarization and repolarization and contractility. Untreated severe hyperkalemia results in sudden cardiac death. Traditional management steps have included reducing dietary potassium and discontinuing potassium supplements; withdrawal of exacerbating drugs; acute treatment with intravenous calcium gluconate, insulin, and glucose; nebulized albuterol; correction of acidosis with sodium bicarbonate for short-term shifts out of the plasma pool; and, finally, gastrointestinal ion exchange with oral sodium polystyrene sulfonate in sorbitol, which is mainly used in the hospital and is poorly tolerated due to gastrointestinal adverse effects. This review explores hyperkalemia as a complication in cardiovascular patients and highlights new acute, chronic, and preventative oral therapies (patiromer calcium, cross-linked polyelectrolyte, ZS-9) that could potentially create a greater margin of safety for vulnerable patients with combined heart and kidney disease.
    Reviews in cardiovascular medicine 01/2014; 15(1):11-23. · 0.58 Impact Factor
  • Gautam R Shroff, Craig A Solid, Charles A Herzog
    [Show abstract] [Hide abstract]
    ABSTRACT: We evaluated temporal trends in ischemic stroke and warfarin use among demographic subsets of the US Medicare population that are not well represented in randomized trials of warfarin for stroke prevention in nonvalvular atrial fibrillation (AF).
    Journal of the American Heart Association. 01/2014; 3(3).
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Structural heart disease is highly prevalent in patients with chronic kidney disease requiring dialysis. More than 80% of end-stage renal disease (ESRD) patients are reported to have cardiovascular disease (CVD). This observation has enormous clinical relevance, as the leading causes of death for ESRD patients are of CVD etiology, including heart failure, myocardial infarction, and sudden cardiac death. The two systems most commonly used to classify the severity of heart failure are the New York Heart Association (NYHA) functional classification and the American Heart Association/American College of Cardiology (AHA/ACC) staging system. With rare exceptions, ESRD patients who do not receive renal replacement therapy (RRT) develop signs and symptoms of heart failure, including dyspnea and edema due to inability of the severely diseased kidneys to excrete sodium and water. Thus, by definition, nearly all ESRD patients develop a symptomatology consistent with heart failure if fluid removal by RRT is delayed. Neither the AHA/ACC heart failure staging nor the NYHA functional classification system identifies the variable symptomatology that ESRD patients experience depending upon whether evaluation occurs before or after fluid removal by RRT. Consequently, the incidence, severity, and outcomes of heart failure in ESRD patients are poorly characterized. The 11th Acute Dialysis Quality Initiative has identified this issue as a critical unmet need for the proper evaluation and treatment of heart failure in patients with ESRD. We propose a classification schema based on patient-reported dyspnea assessed both pre- and post-ultrafiltration, in conjunction with echocardiography.
    Journal of the American College of Cardiology 01/2014; · 14.09 Impact Factor
  • Charles A. Herzog, Gautam R. Shroff
    JACC: Cardiovascular Imaging. 01/2014; 7(7):729–732.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cardiorenal syndromes (CRS) have been recently classified into five distinct entities, each with different major pathophysiologic mechanisms. CRS type 1 most commonly occurs in the setting of acutely decompensated heart failure where approximately 25% of patients develop a rise in serum creatinine and a reduction of urine output after the first several doses of intravenous diuretics. Altered cardiac and renal hemodynamics are believed to be the most important determinants of CRS type 1. CRS type 2 is the hastened progression of chronic kidney disease (CKD) in the setting of chronic heart failure. Accelerated renal cell apoptosis and replacement fibrosis is considered to be the dominant mechanism. CRS type 3 is acutely decompensated heart failure after acute kidney injury from inflammatory, toxic, or ischemic insults. This syndrome is precipitated by salt and water overload, acute uremic myocyte dysfunction, and neurohormonal dysregulation. CRS type 4 is manifested by the acceleration of the progression of chronic heart failure in the setting of CKD. Cardiac myocyte dysfunction and fibrosis, so-called 'CKD cardiomyopathy', is believed to be the predominant pathophysiologic mechanism. Type 5 CRS is simultaneous acute cardiac and renal injury in the setting of an overwhelming systemic insult such as sepsis. In this scenario, the predominant pathophysiological disturbance is microcirculatory dysfunction as a result of acutely abnormal immune cell signaling, catecholamine cellular toxicity, and enzymatic activation which result in simultaneous organ injury often extending beyond both the heart and the kidneys. This paper will summarize these and other key findings from an international consensus conference on the spectrum of pathophysiologic mechanisms at work in the CRS. © 2013 S. Karger AG, Basel.
    Blood Purification 01/2014; 37 Suppl 2:2-13. · 2.06 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The survival outcome following a sudden cardiac arrest (SCA) in hemodialysis (HD) patients is poor regardless of whether an event takes place in or out of a dialysis center. The characteristics of SCA and post-SCA survival with HD patients using a wearable cardioverter defibrillator (WCD) are unknown. All HD patients who were prescribed a WCD between 2004 and 2011 and experienced at least one SCA event were included in this study. Demographics, clinical background, characteristics of SCA events were identified from the manufacturer's database. An SCA event was defined as all sustained ventricular tachycardia/fibrillation (VT/VF) or asystole occurring within 24 hours of the index arrhythmia episode. The social security death index was used to determine mortality after WCD use. A total of 75 HD patients (mean age = 62.9 ± 11.7 years, female = 37.3%) experienced 84 SCA events (119 arrhythmia episodes) while wearing the WCD. Sixty six (78.6%) SCA events were due to VT/VF and 18 (21.4%) were due to asystole. Most SCA episodes occurred between 09:00 and 10:00 (RR = 2.82, 95% CI [1.05, 7.62], P < 0.0001), followed by the 13:00-14:00 time interval (RR = 2.22, 95% CI [0.79, 6.21], P = 0.006). Acute 24-hour survival was 70.7% for all SCA events; 30-day and 1-year survival were 50.7% and 31.4%, respectively. Women had a better post-SCA survival than men (HR = 2.41, 95% CI [1.09, 5.36], P = 0.03). The use of WCD in HD patients was associated with improved post-SCA survival when compared to historical data.
    Annals of Noninvasive Electrocardiology 11/2013; · 1.08 Impact Factor
  • Gautam R Shroff, Craig A Solid, Charles A Herzog
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Few published data describe long-term survival of dialysis patients undergoing surgical versus percutaneous coronary revascularization in the era of drug-eluting stents (DES). METHODS AND RESULTS: Using United States Renal Data System data, we identified 23,033 dialysis patients who underwent coronary revascularization (6178 coronary artery bypass grafting [CABG], 5011 bare-metal stent [BMS], 11,844 DES), 2004-2009. Revascularization procedures decreased from 4347 in 2004 to 3344 in 2009. DES use decreased by 41% and BMS use increased by 85% 2006-2007. Long-term survival was estimated by the Kaplan-Meier method and independent predictors of mortality examined in a comorbidity-adjusted Cox model. In-hospital mortality for CABG patients was 8.2%; all-cause survival at 1, 2, and 5 years was 70%, 57%, and 28% respectively. In-hospital mortality for DES patients was 2.7%; 1, 2, and 5 year survival was 71%, 53%, and 24% respectively. Independent predictors of mortality were similar in both cohorts: age >65 years, white race, dialysis duration, peritoneal dialysis, and congestive heart failure, but not diabetes. Survival was significantly higher for CABG patients who received internal mammary grafts (IMG) (HR 0.83, P<0.0001). Probability of repeat revascularization accounting for the competing risk of death was 18% with BMS, 19% with DES, and 6% with CABG at 1 year. CONCLUSIONS: Among dialysis patients undergoing coronary revascularization, in-hospital mortality was higher after CABG but long-term survival was superior with IMGs. In-hospital mortality was lower for DES patients, but probability of repeat revascularization was higher and comparable to BMS patients. Revascularization decisions for dialysis patients should be individualized.
    Circulation 11/2013; 128(20):e407. · 15.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Context:The clinical course of secondary hyperparathyroidism (sHPT) in patients on hemodialysis is not well described, and the effect of the calcimimetic cinacalcet on disease progression is uncertain.Objective:To describe (a) the clinical course of sHPT in patients treated with phosphate binders and/or vitamin D sterols and (b) the impact of cinacalcet on occurrence of severe unremitting HPT, defined by the persistence of markedly elevated parathyroid hormone (PTH) concentrations together with hypercalcemia or parathyroidectomy (PTX).Design:Randomized, double-blind, placebo-controlled clinical trial.Setting:Global, multicenter.Patients:3883 patients on hemodialysis of 5755 screened with moderate to severe sHPT.Main outcome measures:Parathyroidectomy, severe, unremitting HPT and use of commercial cinacalcet (a protocol violation).Intervention:Cinacalcet (30 to 180 mg daily) or placebo for up to 64 months.Results:In the 1935 patients randomized to placebo, 278 (14%) patients underwent PTX (median PTH 1872 pg/mL within prior 12 weeks of surgery). Age, sex, geographic region, co-morbidity, calcium-containing phosphate binder use, and baseline serum calcium, phosphorus and PTH concentrations were associated with PTX. Commercial cinacalcet was started in 443 (23%) patients (median PTH 1108 pg/mL before treatment began). Severe unremitting HPT developed in 470 (24%) patients. In a multivariable Cox model, the relative hazard (comparing patients randomized to cinacalcet versus placebo) of severe unremitting HPT was 0.31 (95% CI 0.26 to 0.37). The relative hazard differed little when adjusted by baseline clinical characteristics.Conclusions:Severe unremitting HPT develops frequently in patients on hemodialysis despite conventional therapy, and cinacalcet substantially reduces its occurrence.
    The Journal of Clinical Endocrinology and Metabolism 10/2013; · 6.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The lack of evidence on the effectiveness and safety of interventions in chronic dialysis patients has been a subject of continuing criticism. New technologies are often introduced into the market without having specifically studied or even included patients with advanced kidney disease. Therefore, the need to generate valid effectiveness and safety data in this vulnerable subpopulation is of utmost importance. The US Food and Drug Administration has recently placed an increased focus on safety surveillance, and sponsors must now meet this additional postmarketing commitment. In patients with ESRD, the unique data collection environment in the United States allows for creative and efficient study designs to meet the needs of patients, providers, and sponsors. The purpose of this manuscript is to review the methodological and practical aspects of the different options for postmarketing study design in this field, with critical appraisal of their advantages and disadvantages.
    Clinical Journal of the American Society of Nephrology 08/2013; · 5.07 Impact Factor
  • Gautam R Shroff, Charles A Herzog
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with advanced chronic kidney disease sustain extremely high mortality rates following acute myocardial infarction. Nauta et al. evaluated temporal trends in 12,087 patients with acute myocardial infarction from a single institution over 24 years and report a reduction in 30-day mortality in the most recent decade for all patients, including patients with chronic kidney disease. This trend is optimistic, but understanding contributory factors would be critical in future studies to further improve survival.
    Kidney International 08/2013; 84(2):230-3. · 8.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Bacterial endocarditis in dialysis patients is associated with high mortality rates. The literature is limited regarding long-term outcomes of valvular replacement surgery and choice of prosthesis in dialysis patients with bacterial endocarditis. METHODS AND RESULTS: Dialysis patients hospitalized for bacterial endocarditis, 2004-2007, were studied retrospectively using data from the US Renal Data System. Long-term survival of patients undergoing valve replacement surgery with tissue or non-tissue valves was compared using the Kaplan-Meier method. A Cox proportional hazards model was used to identify independent predictors of mortality in patients undergoing valvular replacement surgery. During the study period, 11,156 dialysis patients were hospitalized for bacterial endocarditis and 1267 (11.4%) underwent valvular replacement surgery (tissue valve 44.3%, non-tissue valve 55.7%). In the valve replacement cohort, 60% were men, 50% white, 54% aged 45-64 years, and 36% diabetic. Estimated survival with tissue and non-tissue valves, respectively, at 0.5, 1, 2, and 3 years was 59% and 60%, 48% and 50%, 35% and 37%, and 25% and 30% (log rank P = 0.42). Staphylococcus was the predominant organism (66% of identified organisms). Independent predictors of mortality in patients undergoing valve replacement surgery included older age, diabetes as cause of end-stage renal disease, surgery during index hospitalization, staphylococcus as the causative organism, and dysrhythmias as a comorbid condition. CONCLUSIONS: Valve replacement surgery is appropriate for well-selected dialysis patients with bacterial endocarditis, but is associated with high mortality rates. Survival does not differ with tissue or non-tissue prosthesis.
    Circulation 06/2013; · 15.20 Impact Factor
  • Gautam R. Shroff, Craig A. Solid, Charles A. Herzog
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Few published data describe long-term survival of dialysis patients undergoing surgical versus percutaneous coronary revascularization in the era of drug-eluting stents (DES). METHODS AND RESULTS: Using United States Renal Data System data, we identified 23 033 dialysis patients who underwent coronary revascularization (6178 coronary artery bypass grafting, 5011 bare metal stents, 11 844 DES) from 2004 to 2009. Revascularization procedures decreased from 4347 in 2004 to 3344 in 2009. DES use decreased by 41% and bare metal stent use increased by 85% from 2006 to 2007. Long-term survival was estimated by the Kaplan-Meier method, and independent predictors of mortality were examined in a comorbidity-adjusted Cox model. In-hospital mortality for coronary artery bypass grafting patients was 8.2%; all-cause survival at 1, 2, and 5 years was 70%, 57%, and 28%, respectively. In-hospital mortality for DES patients was 2.7%; 1-, 2-, and 5-year survival was 71%, 53%, and 24%, respectively. Independent predictors of mortality were similar in both cohorts: age >65 years, white race, dialysis duration, peritoneal dialysis, and congestive heart failure, but not diabetes mellitus. Survival was significantly higher for coronary artery bypass grafting patients who received internal mammary grafts (hazard ratio, 0.83; P<0.0001). The probability of repeat revascularization accounting for the competing risk of death was 18% with bare metal stents, 19% with DES, and 6% with coronary artery bypass grafting at 1 year. CONCLUSIONS: Among dialysis patients undergoing coronary revascularization, in-hospital mortality was higher after coronary artery bypass grafting, but long-term survival was superior with internal mammary grafts. In-hospital mortality was lower for DES patients, but the probability of repeat revascularization was higher and comparable to that in patients receiving a bare metal stent. Revascularization decisions for dialysis patients should be individualized.
    Circulation 05/2013; 127(18):1861. · 15.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The incidence of stroke is substantially higher among hemodialysis patients than among patients with earlier stages of CKD, but to what extent the initiation of dialysis accelerates the risk for stroke is not well understood. In this cohort study, we analyzed data from incident hemodialysis and peritoneal dialysis patients in 2009 who were at least 67 years old and had Medicare as primary payer. We noted whether each of the 20,979 hemodialysis patients initiated dialysis as an outpatient (47%) or inpatient (53%). One year before initiation, the baseline stroke rate was 0.15%-0.20% of patients per month (ppm) for both outpatient and inpatient initiators. Among outpatient initiators, stroke rates began rising approximately 90 days before initiation, reached 0.5% ppm during the 30 days before initiation, and peaked at 0.7% ppm (8.4% per patient-year) during the 30 days after initiation. The pattern was similar among inpatient initiators, but the stroke rate peaked at 1.5% ppm (18% per patient-year). For both hemodialysis groups, stroke rates rapidly declined by 1-2 months after initiation, fluctuated, and stabilized at approximately twice the baseline rate by 1 year. Among the 620 peritoneal dialysis patients, stroke rates were slightly lower and variable, but approximately doubled after initiation. In conclusion, these data suggest that the process of initiating dialysis may cause strokes. Further studies should evaluate methods to mitigate the risk for stroke during this high-risk period.
    Journal of the American Society of Nephrology 04/2013; · 8.99 Impact Factor
  • Louis P Kohl, Gautam R Shroff, Charles A Herzog
    Clinical Chemistry 04/2013; · 7.15 Impact Factor
  • Gautam R Shroff, Charles A Herzog
    Clinical Journal of the American Society of Nephrology 02/2013; · 5.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Reliable data regarding absolute and relative risks of death and graft failure after coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) in renal transplant patients are unavailable. Renal transplant patients undergoing inpatient CABG (n=1400) or PCI (n=4097) were identified from United States Renal Data System data. Cumulative incidence of nonfatal graft failure and death was reported for observed events. A Cox model with the Fine-Gray method was used to account for competing risks in assessing relative hazards. Age and race were similarly distributed; patients who underwent CABG were more likely to have acute arrhythmia and congestive heart failure but less likely to have acute myocardial infarction on index admission. In-hospital death was more frequent after CABG (5.6% versus 3.0%, P<0.001). Cumulative incidence of death, graft failure, and the combined outcome at 3 years were 23.1%, 15.4%, and 38.5% after CABG and 22.9%, 13.3%, and 36.1% after PCI, respectively. In adjusted analyses, CABG was not associated with increased risk of graft failure versus PCI during the first 6 months (hazard ratio 1.06, 95% CI 0.79 to 1.43) or from 6 to 36 months (0.98, 0.78 to 1.22). Risk of death increased after CABG during the first 3 months (1.37, 1.08 to 1.73), but decreased from 6 months on (0.76, 0.63 to 0.93). CABG does not appear to be associated with a difference in risk of graft failure compared with PCI in renal transplant patients. Compared with PCI, adjusted risk of early death is higher after CABG; however, mortality from 6 months on is lower.
    Journal of the American Heart Association. 01/2013; 2(1):e003558.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In developed countries, the continuing rise in the prevalence of hypertension, hyperlipidemia and diabetes has contributed to an overall increase in the incidence of both cardiovascular disease (CVD) and chronic kidney disease (CKD). The observation that even modest reductions in renal function correlate with increased CVD morbidity and mortality has led to the recognition that CKD is an independent risk factor for CVD. Conversely, there is a growing recognition that many pathologic conditions that contribute to CVD, including coronary artery disease, left ventricular hypertrophy and diastolic dysfunction, can accelerate the decline in renal function. In addition, physiologic mechanisms designed to compensate for reduced glomerular filtration rate including activation of the renin-angiotensin-aldosterone axis, the release of fibroblastic growth factor 23 and other mechanisms for calcium-phosphate homeostasis as well as and the pathophysiologic effects of uremic toxins can also directly contribute to CVD. The end result of the interaction between changes in pressure and volume overload and the physiologic compensation for the loss of function in both the heart and the kidney leads to accelerated decline in both organ systems. This complex physiologic and pathophysiologic interplay between the cardiovascular and renal systems is collectively referred to as the cardiorenal syndrome. The discussion which follows is aimed at outlining the pathophysiologic mechanisms linking advanced CKD (4 and 5) to the development of cardiac abnormalities which occur with unique frequency and severity in patients with severe impairment of renal function.
    Contributions to nephrology 01/2013; 182:158-173. · 1.49 Impact Factor

Publication Stats

5k Citations
999.28 Total Impact Points

Institutions

  • 1988–2014
    • Hennepin County Medical Center
      • Department of Emergency Medicine
      Minneapolis, Minnesota, United States
  • 2013
    • Brigham and Women's Hospital
      • Department of Medicine
      Boston, MA, United States
    • University of Tennessee
      Knoxville, Tennessee, United States
  • 2002–2013
    • University of Minnesota Duluth
      • Medical School
      Duluth, Minnesota, United States
  • 2012
    • National Institutes of Health
      • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
      Bethesda, MD, United States
    • Abbott Northwestern Hospital
      Minneapolis, Minnesota, United States
    • McMaster University
      • Division of Neurology
      Hamilton, Ontario, Canada
  • 2011
    • George Eliot Hospital NHS Trust
      Nuneaton, England, United Kingdom
    • University of Texas Health Science Center at San Antonio
      • Department of Neurology
      San Antonio, TX, United States
  • 2002–2011
    • University of Minnesota Twin Cities
      • • Department of Pediatrics
      • • Division of Cardiology
      • • Department of Laboratory Medicine and Pathology
      Minneapolis, MN, United States
  • 2007
    • St George's Healthcare NHS Trust
      Londinium, England, United Kingdom
  • 2006
    • Emory University
      • Department of Rehabilitation Medicine
      Atlanta, GA, United States
  • 2005
    • Minneapolis Veterans Affairs Hospital
      Minneapolis, Minnesota, United States
  • 2001–2005
    • Minneapolis Medical Research Foundation
      Minneapolis, Minnesota, United States
  • 1998
    • Minneapolis Heart Institute
      Minneapolis, Minnesota, United States