For Medical Professionals

Anticoagulation Clinics of North America (ACNA) is a network of anticoagulation clinics based on the principal that the maximum benefit of anticoagulation with the least risk is attainable through a dedicated anticoagulation management clinic.  ACNA was founded in 1994 to assist the physician in optimizing the efficacy and safety of antithrombotic therapy.  Through advancements in technology and clinical research, ACNA has formulated an unparalleled system for managing anticoagulation therapy for physicians and their patients.

With our approach to management, complications from bleeding and thrombosis were reduced by 50-80%.  Our ACNA program produced an average time in the INR range of 69.63% and 87.77% if the range is expanded by only +/-0.3 INR units.  This level of INR control is well above the 50-60% time in range seen with typical anticoagulation management.  The best results are obtained when patients are kept tightly in their designated range based on their risk for forming clots versus the risk of bleeding.

The ACNA Clinic

An anticoagulation clinic is an organized system to coordinate anticoagulation care for your patients.  Patients are seen face-to-face in an office setting where vital signs are taken, limited physical exams may be done, and concerns can be addressed. Rapid laboratory results allow us to give your patients written dosing instructions during the exam visit. Future visits are scheduled before patients leave the clinic to assure continued follow-up.

The ACNA Procedure

The most appropriate anticoagulation regimen and the optimal intensity and length of anticoagulation treatment is determined after thorough assessment of the patient’s risk of bleeding and thrombosis.  Each patient visit involves a highly-trained anticoagulation clinician.  Extensive and individualized patient education is given on the first visit and the education is reinforced at subsequent visits.  Our lab is strictly controlled for quality, and processes blood samples rapidly.  Unexpected results may be checked by an alternative method.  Dosage instructions are provided on a written dosage card and reviewed with the patient.  Standard procedure includes on-going communication with the patient’s physician, blood counts every 3 months, stool testing for bleeding is done yearly, and a yearly ACNA physician appointment.

  • Out-patient and in-patient visits
  • Hematologist available for hospital consults
  • Rapid in-house PT/INR results
  • Same-day dose management
  • Management for dental work or surgery
  • Quality Control
  • Data management
  • Timely reports back to referring physician


Indications for Referrals

  • LV Thrombus
  • MI
  • CAD
  • CAGB
  • Low LVEF
  • Diabetes
  • Hypertension
  • Pacemaker
  • Age >65
  • Previous stroke, TIA


Physicians and patients may be reluctant to use warfarin because of the fear of bleeding and/or unacceptability of close monitoring.  Aspirin is perceived to be less dangerous than warfarin.  However, when monitored appropriately, the risk of bleeding with warfarin is not significantly different than the risk of bleeding with aspirin or placebo.

Should warfarin (Coumadin) be considered for a patient with atrial filbrillation who has been maintained successfully with aspirin for 10 years?

Current guidelines (*CHEST, 2004) advocate the use of warfarin preferentially for stroke prophylaxis in atrial fibrillation.  Should all patients be converted to warfarin?  Studies that have shown efficacy target the INR range between 2.0 and 3.0.  An INR of 1.7 provides one-half the protection of an INR of 2.0.  At an INR of 1.5, most of the efficacy of warfarin in atrial fibrillation is lost.  When study data were analyzed for only those patients who were actually taking warfarin, an 85% reduction in stroke was observed.

*Singer DE, Albers GW, Dalen JE, et al., Antithrombotic therapy in atrial filbrillation, CHEST, 2004, 126 (3)(suppl):4295-4565.  For full list of other references, and more information, please contact us at .(JavaScript must be enabled to view this email address), or call the clinic at 210-595-5300.

ACNA Contact Information and Locations

For hospital consultations OR patient referrals, please call 210-595-5300.


ACNA Clinicians

Roger M. Lyons, MD, FACP, Medical Director of ACNA

Henry I. Bussey, PharmD., FCCP, Clinical Director of ACNA

Catarina Do, PA-C

Robert Scott Kronenthal, MSN, RN, CS-FNP

Michael W. Vermeulen, MPAS, PA-C

Suzanne McGregor, MSN, RN, FNP/GNP-BCrs

Erica Carone, RPA-C

Links to other relevant websites

Anticoagulation FORUM
acforum.org

The Thrombosis Interest Group of Canada
tigc.org

ClotCare Online Resource
Clotcare.com

American Venous Forum
venous-info.com