Director's Forum

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A Patient with Chronic Atrial Fibrillation

by David B. Troxel, MD, Medical Director, Board of Governors

This 52-year-old female was diagnosed with hypertension in May 2000 (BP 144/116) by her primary care physician (PCP) and placed on a low dose of hydrochlorothiazide. After starting an exercise program in 2001, her blood pressure returned to normal.

In August 2001, the patient was scheduled for minor surgery, and a preoperative EKG revealed atrial fibrillation (AF). She was referred to a partner of our insured cardiologist, who placed her on Coumadin prior to elective cardioversion. This was initially successful but lasted only a short time. In October, she was seen by our insured cardiologist with complaints of fatigue. Her blood pressure was normal. In consultation with another associate, an electrophysiologist, the Coumadin was continued, and she underwent two cardioversions. After loading and then increasing the dose of Rythmol (propafenone), she returned to normal sinus rhythm (NSR), but only briefly.

In January 2002, she returned to the insured’s associate electrophysiologist. She was in AF and was very fatigued, but he was reluctant to treat her with amiodarone because of potential side effects. She continued on Coumadin and failed to keep her six-month follow-up appointment. In April, she saw her PCP and was in NSR. Her International Normalized Ratio (INR) was 2.0, and she remained on Coumadin. Ablation was discussed, but she refused because it wasn’t covered by insurance.

In October, she saw a new arrhythmia consultant in a different cardiology practice. She was in AF, and he started her on flecainide 50 mg twice daily. Three weeks later the dose was increased to 100 mg twice daily. When seen again in December, she was in NSR with a rate of 60. She remained on flecainide, but the Coumadin was stopped. When next seen by this consultant in October 2003, she remained in NSR, and he advised her to stay on flecainide and return in one year. She returned in May 2005 in NSR and was continued on flecainide.

When she returned in February 2006, she was in AF. He prescribed Coumadin 5 mg daily for the next three days and referred her for a transesophageal echocardiogram (TEE) with immediate cardioversion if the TEE was negative for thrombi. She was instructed to return in one week. She did not keep the TEE appointment and apparently did not take the Coumadin because five days later her prothrombin time was normal and the INR was 1.1. Three days later, she returned to her PCP in AF. When she refused cardioversion or hospital admission, he advised her to find another PCP and to see a cardiologist.

What Would You Have Done? 
The patient returned to our insured cardiologist a few weeks later. She had not seen him since 2001. She was in AF and said that sometimes her heart rate was too fast. The insured recommended pulmonary vein ablation, stating that it had a 60 percent success rate in eliminating AF. He did not believe she was a candidate for Coumadin because she was less than 60 years of age and did not have clinical or echocardiographic evidence of heart disease (“lone AF”). He calculated her CHADS2 stroke risk assessment score* as 0. He felt she fell into the category of “low-risk atrial fibrillation,” for which the treatment would be either aspirin or nothing. She was given a prescription for Tenormin (atenolol) to control her heart rate, and when she left the office, she was in NSR. A referral was made for the vein ablation procedure. Two days later, she returned to the insured for a stress test and echocardiogram. Both were normal, and she remained in NSR. The insured never heard from the patient again.

Eight days later, she was admitted to the hospital with a stroke. She now has residual left-sided weakness, limited use of her left upper extremity, left-sided visual impairment, memory loss, and cognitive deficits.

Expert Opinions 
Plaintiff: A board certified cardiologist opined that failure to administer anticoagulant therapy was below the standard of practice.

Defense: The case was reviewed favorably by a board certified cardiologist. He opined that the patient’s young age, coupled with the lack of structural heart disease, qualified her as having lone atrial fibrillation, for which Coumadin anti-coagulation is not generally recommended and aspirin’s effectiveness remains controversial. The fact that she frequently was in NSR decreased her embolic risk further. He stated the standard of care did not require use of anticoagulant therapy.

A board certified cardiologist specializing in cardiac electrophysiology was initially critical of not putting the patient on Coumadin because her history of hypertension took her out of the lone atrial fibrillation category and out of the low-risk group for thromboembolism as defined in the risk-stratification scheme in the 2001 Guidelines for the Management of Patients with Atrial Fibrillation.¹ However, on reflection he stated that physicians must consider each patient individually to decide if a history of hypertension is clinically significant because anticoagulation with Coumadin carries risks. He stated that the current 2006 Guidelines² do not require Coumadin for atrial fibrillation when there is a history of hypertension and that either Coumadin or aspirin can be used. Nevertheless, he believed that had she been put on Coumadin, she would not have had the stroke, adding that many experts would state that she needed to be on Coumadin.

Analysis
The issues in this claim became whether or not the insured cardiologist should have put the patient on Coumadin and if doing so would have prevented her stroke. The 2001 Guidelines for the Management of Patients with Atrial Fibrillation recommended using risk factors (age, gender, diabetes, coronary artery disease, left ventricular dysfunction, hypertension, and history of hypertension) to guide anticoagulant therapy. New guidelines released in August 2006 include additional risk factors for stroke (previous stroke, TIA or embolization, mitral stenosis, prosthetic heart valve, and heart failure) without mention of history of hypertension. The 2001 guidelines apply to this case because the insured initially saw the patient in October 2001, at which time he continued her Coumadin and next saw her in March 2006, when he did not. The insured’s office records document her history of hypertension—so her CHADS₂ stroke risk score was 1 (not 0, as the insured calculated).

Expert support was marginal, and damages were significant because the plaintiff was a relatively young woman in generally good health prior to her stroke. A trial would become a “battle of experts” in a venue that often produced high verdicts. The insured was on the verge of retirement. He was likeable but didn’t appear to be up to date on current medical practices. At his deposition, he was easily confused by the plaintiff’s attorney’s questions and testified that if the patient had a history of hypertension, he would have placed her on Coumadin. Her history of hypertension was documented in his office chart—and he had not placed her on Coumadin. At the insured’s request, the claim was settled.

Discussion
In a review of 363 consecutive closed claims at The Doctors Company, 9.6 percent contained medication-related errors. Forty-three percent of the medication-related errors involved monitoring, and one-third of these involved failure to properly monitor Coumadin. Thus, 1.4 percent of claims contained Coumadin monitoring errors. In a review of 130 closed internal medicine claims containing repetitive clinical events, six claims involved the mismanagement of anticoagulants in patients with atrial fibrillation—resulting in hemorrhage (four) or embolization (two).

These reviews highlight the malpractice risks associated with use of anticoagulants, particularly Coumadin—and the importance of properly monitoring Coumadin with the INR. When either hemorrhage or embolization occurs in a patient on Coumadin, the plaintiff’s experts will scrutinize the medical record to see if the patient’s INR was in the therapeutic range.

This case also illustrates the importance of being familiar with practice guidelines. While it isn’t essential to always follow guidelines or to follow them exactly (after all, they are “guidelines” and will not be applicable to every patient in every clinical setting), if you decide not to follow them, you should document your reasons in the medical record. Otherwise, should a claim arise, the plaintiff may argue that you were unfamiliar with the applicable guideline and that your failure to follow it was below the standard of practice and caused patient injury.

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