What is the best course of action for a patient with mild aortic stenosis, arrhythmia, hyperlipidemia, and hypertension, who recently underwent a stress test with abnormal ECG results showing frequent premature ventricular contractions (PVCs), occasional ventricular couplets, and a single ventricular triplet, with equivocal ischemic ECG changes in the inferior leads, and is currently taking an angiotensin receptor blocker (ARB), aspirin, and a statin?

Management of Abnormal Stress Test with Ventricular Arrhythmias and Equivocal Ischemia in Mild Aortic Stenosis

This patient requires coronary angiography to definitively evaluate the equivocal ischemic changes, combined with advanced imaging (stress echocardiography or nuclear perfusion) to assess both functional significance of the aortic stenosis and true ischemic burden, while continuing current medical therapy and adding beta-blocker therapy for ventricular arrhythmia suppression.

Immediate Risk Stratification

The Duke treadmill score of 2 indicates moderate risk, which warrants further investigation rather than conservative management alone 1. The combination of equivocal ischemic ECG changes in inferior leads, exercise-induced ventricular arrhythmias (PVCs, couplets, and triplet), and hypertensive response creates diagnostic uncertainty that cannot be dismissed 1.

Key Concerning Features:

• Equivocal ischemic changes in inferior leads during early recovery suggest possible coronary artery disease, though the rapid resolution (40 seconds) and absence of chest pain reduce the likelihood of high-grade stenosis 1
• Ventricular arrhythmias (frequent PVCs, couplets, single triplet) that failed to suppress with maximal exertion are abnormal and require evaluation, as they may indicate underlying structural heart disease or ischemia 1
• Hypertensive response (peak 174/68 mmHg) in the context of mild aortic stenosis is significant, as hypertension accelerates stenosis progression and worsens left ventricular remodeling 2

Recommended Diagnostic Pathway

Step 1: Coronary Angiography

Proceed with invasive coronary angiography to definitively exclude obstructive coronary artery disease 1. The ACC/AHA guidelines state that patients with abnormal stress tests showing ischemic changes should undergo diagnostic angiography, even when findings are equivocal 1. This is particularly important because:

• Approximately 32.5% of patients with abnormal stress imaging have false-positive results (<50% stenoses), but these patients still require intensive risk factor management and have similar outcomes to those with true-positive results 3
• The inferior lead changes, though equivocal, combined with multiple cardiovascular risk factors (hyperlipidemia, hypertension) justify anatomic evaluation 1

Step 2: Stress Echocardiography for Aortic Stenosis Assessment

Perform exercise stress echocardiography to evaluate the hemodynamic significance of the mild aortic stenosis 1, 4. This is critical because:

• Exercise stress echo is safe in asymptomatic aortic stenosis patients and provides prognostic information beyond exercise testing alone 1, 4
• The test should measure mean pressure gradient increase and systolic pulmonary artery pressure at peak exercise 1
• An increase in mean gradient ≥18-20 mmHg or induced pulmonary hypertension (SPAP >60 mmHg) indicates poor prognosis and may warrant earlier intervention 1
• Stress testing in asymptomatic severe AS is safe with no sudden deaths reported in patients with normal stress test results after 1 year 4

Important caveat: While one study suggested that MPG increase >20 mmHg and peak SPAP >60 mmHg were not predictive of outcomes in their cohort 5, the European Heart Journal guidelines still recommend these parameters for risk stratification 1, and the safety profile supports performing the test.

Medical Management Optimization

Hypertension Control

Intensify blood pressure management targeting systolic BP 130-139 mmHg and diastolic 70-90 mmHg 2. The current hypertensive response during stress (174/68 mmHg) is concerning:

• Continue the angiotensin receptor blocker (ARB), as renin-angiotensin system blockers improve survival in aortic stenosis patients both before and after valve intervention 2
• The ARB is safe in mild aortic stenosis with preserved left ventricular function; ACE inhibitors have been shown to be well-tolerated in mild-moderate AS without significant hemodynamic changes 6
• Avoid calcium channel blockers, as they may be associated with lower survival in aortic stenosis 2
• Consider adding a beta-blocker for dual benefit: blood pressure control and ventricular arrhythmia suppression 2

Arrhythmia Management

Initiate beta-blocker therapy for the exercise-induced ventricular arrhythmias 2. Beta-blockers are:

• Well-tolerated in aortic stenosis patients 2
• Particularly appropriate given the patient's hypertension and arrhythmias 2
• The preferred choice when concomitant coronary artery disease is present (which remains to be determined) 2

Continue Current Therapy

• Maintain aspirin for cardiovascular risk reduction 1
• Continue statin for hyperlipidemia management 1

Clinical Algorithm Summary

1. Obtain coronary angiography to evaluate equivocal ischemic changes 1
2. Perform exercise stress echocardiography to assess aortic stenosis hemodynamic significance and measure MPG increase and SPAP at peak exercise 1, 4
3. Add beta-blocker to current ARB, aspirin, and statin regimen 2
4. Target BP 130-139/70-90 mmHg with current medications 2
5. Avoid diuretics unless volume overload develops, as they may be disadvantageous with left ventricular hypertrophy 2

Follow-Up Monitoring

• Serial echocardiography every 6-12 months to monitor aortic stenosis progression 1
• Ambulatory ECG monitoring (Holter or event monitor) to quantify arrhythmia burden and assess response to beta-blocker therapy 1
• Symptom surveillance for development of angina, dyspnea, syncope, or heart failure symptoms that would mandate intervention 1, 4

Critical Pitfalls to Avoid

• Do not dismiss equivocal ischemic changes without anatomic evaluation, as false-positive stress tests still identify patients requiring intensive management 3
• Do not assume mild aortic stenosis is benign in the presence of hypertension, as this accelerates disease progression 2
• Do not use calcium channel blockers for blood pressure control in this patient 2
• Do not delay angiography based solely on absence of chest pain, as the Duke score and ECG changes warrant investigation 1