Managing Heart Failure in the Family Practice Setting

Managing Heart Failure in the Family Practice Setting

Authored by: J. Frank Martin, Jr., M.D.

The Problem

Heart failure is a hemodynamic disorder that affects nearly 5.7 million Americans with an additional 670,000 diagnoses each year.¹  It is characterized by symptoms of fatigue, shortness of breath with or without exertion, and edema.  Primary care providers need to stay current on the evaluation and management of heart failure as they routinely manage chronic (long-term) heart failure patients in the outpatient clinic.  

There are two types of heart failure; systolic heart failure, which is the inability of the left ventricle to contract strongly enough to expel a sufficient amount of blood to the body and diastolic heart failure, which means the inability of the left ventricle to fill adequately, also preventing sufficient flow of blood to the body.  Both types of heart failure present with the same symptoms. 

The underlying cause of systolic heart failure, the most common type, can be ischemic or non-ischemic.  Ischemic systolic heart failure is caused by preexisting coronary artery disease while non-ischemic, is primarily due to structural changes resulting from familial genetics, viral illness, valvular disease, and alcoholism.  Diastolic heart failure will occur as a result of long-term, chronic hypertension. 

The primary goal in the management of chronic heart failure patients is to improve cardiac function and reduce symptoms.  The goal of medication therapy is to relieve symptoms of congestion.  Medical therapy for patients with heart failure requires the prescription of several categories of cardiac medications coupled with lifestyle changes that decrease symptoms and hospitalizations, and improve quality of life.  These medical categories include beta blockers, ace inhibitors, angiotensin receptor blockers and other vasodilators, inotropes, and diuretics.  Acute heart failure is the sudden onset of patient symptoms and requires emergent treatment typically followed by hospitalization for aggressive medical management.

The physical examination of heart failure patients is used to determine the patient’s level of perfusion and congestion.  To determine levels of perfusion or amount of blood flow to the body, the physician assesses the patient’s pulse pressure, temperature of the skin, and assesses the level of congestion by performance of the hepato-jugular reflex, inspection of pulsation in the jugular neck vein, lung auscultation for rales, and examination for pedal/sacral edema.  This physical examination is used as a surrogate for determining hemodynamic implications.  Until now, this was the only non-invasive method to make this assessment in the outpatient setting.

Impedance Cardiography

Today, new technology called impedance cardiography (ICG) or noninvasive hemodynamics is used to assist the physician in managing the chronic heart failure patient at the point of care.  ICG can be used to provide short-term prognostic patient information.  ICG is conducted by office staff in a five minute, simple test.  Just as the EKG provides the physician with information regarding the electrical activity of the heart, ICG provides the physician with the mechanical activity of the heart.  ICG uses four sets of dual sensors placed on each side of the neck beneath the earlobes, and on each side of the chest at the level of the xiphoid process, laterally.  A low amplitude, high frequency electrical current is delivered to the thorax through four sensors.  Resistance to the current is measured via the four remaining sensors with each heart beat.   The signal is processed and analyzed to provide the following hemodynamic information:  measurements of flow (cardiac output/index, stroke volume/index), measurements of resistance (systemic vascular resistance/index), measurements of contractility (left ventricular ejection time, pre-ejection period, systolic time ratio), and measurements of fluid (thoracic fluid content). 

All cardiac medications are prescribed so as to affect hemodynamics in various forms; by negatively or positively altering the heart rate, changing the flow of blood by altering preload or blood volume (TFC), afterload or amount of tone of the arterial vascular system (SVR/SVRI), or changing contractility (LVET, PEP, STR).  Therefore, prescribing any one of the cardiac drug categories will affect the hemodynamics of a patient.   Diuretics affect the preload, ACE inhibitors and other vasodilators affect the level of systemic vascular resistance, inotropic agents and beta-blockers affect measurements of contractility.  This becomes important because if heart failure is a hemodynamic disorder, it is plausible to determine which hemodynamic parameter(s) are out of range and target appropriate medical therapy to bring the patient into a normal hemodynamic state. 

Clinical Studies

PRospective Evaluation of Cardiac Decompensation in Patients with Heart Failure by Impedance Cardiography Test: The PREDICT Multicenter Trial was published in the Journal of American College of Cardiology (JACC).  Principal investigator was Milton Packer, M.D.  The purpose of the study was to determine whether noninvasive hemodynamic parameters from ICG were predictive of HF events in the short-term.  An HF event was defined as heart failure-related hospitalization or ED visit, or all-cause mortality.  212 patients at 21 study centers with over 2300 patient visits were evaluated.  Baseline patient characteristics plus standard clinical variables and ICG were measured every two weeks.  The results indicated that if a HF patient’s stroke index (SI) was ≤35 and thoracic fluid content (TFC) value was >35, the patient was seven times more likely to have a HF event in the short-term (14 days) than those that were in the low risk group (SI >35 and TFC ≤35).² 

Case Study³

 History:  This 52 year old male with a history of heart failure presented to the office on 4/7/2005 experiencing shortness of breath.

Current Therapy:  lisinopril 20 mg daily; lasix 40 mg daily and KCl twice daily. 

HR                        92

BP                        108/78

SI                        22

CI                        2.0

SVRI                        3145

TFC                        41.6

STR                        0.40

ICG Analysis:  low cardiac output and high SVRI

Treatment Decisions:  Start the patient on irbesartan 150 mg daily and return to the office in two months.

Post treatment:  At the second visit, the cardiac output increased, heart rate decreased and SVR decreased.  TFC also decreased and shortness of breath improved.

HR                        79

BP                        111/73

SI                        37

CI                        2.9

SVRI                        2155

TFC                        33.6

STR                        0.36

Reimbursement

ICG is nationally-approved by the Centers for Medicare and Medicaid Services (CMS) for five patient indications including symptoms of heart failure which include fluid management and dyspnea.  The CPT code is 93701. 

¹Heart Failure. American Heart Association Website.  2009.  Available at: http://www.americanheart.org/presenter.jhtml?identifier=1486.  Accessed September 2, 2009.

²Packer M, Abraham WT, Mehra MR, Yancy CW, et al. J Am Coll Cardiol. 2006 Jun 6;47(11):2245-52.

³Case study from CardioDynamics study arc