Can beta blockers be given to a patient with a 2-week history of intermittent angina (chest pain), considering potential contraindications such as bronchial asthma, severe chronic obstructive pulmonary disease (COPD), or heart failure?

Beta-Blockers for Intermittent Angina Over 2 Weeks

Yes, beta-blockers should be initiated orally in patients with a 2-week history of intermittent angina, provided there are no absolute contraindications such as active asthma, severe heart failure with decompensation, significant bradycardia (<50 bpm), hypotension (systolic BP <90-100 mmHg), or high-degree AV block. 1

Initial Assessment and Contraindications

Before prescribing beta-blockers, you must exclude the following absolute contraindications:

• Active asthma is an absolute contraindication 1, 2
• Severe decompensated heart failure (presence of rales, S3 gallop, or signs of cardiogenic shock) 1
• Significant bradycardia (heart rate <50 bpm) 1
• Hypotension (systolic blood pressure <90-100 mmHg) 1, 2
• High-degree AV block (second- or third-degree block, or first-degree block with PR interval ≥0.24 seconds without a pacemaker) 1, 2
• Evidence of low cardiac output (oliguria, confusion) 1

Approach Based on Respiratory Comorbidities

COPD Without Asthma

Beta-1 selective agents (cardioselective) are NOT contraindicated in COPD and should be used. 1, 3

• Bisoprolol is the preferred agent due to its high beta-1 selectivity 1, 3
• Alternative cardioselective agents include metoprolol succinate or nebivolol 3
• Start with low doses: bisoprolol 1.25 mg daily, metoprolol succinate 12.5-25 mg daily 3
• The critical factor is bronchial hyperreactivity, not simply airflow obstruction 3
• Cardioselective beta-blockers may paradoxically improve bronchial responsiveness and survival in COPD 1

COPD With Positive Bronchoreactivity or Active Asthma Component

Beta-blockers are contraindicated. 1

• Use alternative heart rate-lowering agents: ivabradine, diltiazem, or verapamil 1
• For angina control with preserved ventricular function, use calcium-channel blockers or nitrates 1

Mild Wheezing or Mild COPD

A cautious trial of low-dose cardioselective beta-blocker is reasonable. 1

• Start with very low dose (e.g., metoprolol 12.5 mg orally) 1, 4
• Use short-acting cardioselective agents initially to assess tolerability 1
• Ensure bronchodilators (beta-2 agonists) are readily available 2
• Monitor for wheezing, increased dyspnea, or bronchospasm 3, 4

Initiation Strategy for Angina

Route and Timing

Oral administration should be started early (within first 24 hours) in the absence of contraindications. 1

• Intravenous beta-blockers should be reserved for specific indications: ongoing rest pain with tachycardia or hypertension, and only in hemodynamically stable patients 1
• Avoid aggressive early IV beta-blockade in patients with heart failure or risk factors for cardiogenic shock 1

Agent Selection

Beta-blockers without intrinsic sympathomimetic activity are preferred. 1

• Agents studied in acute coronary syndromes include metoprolol, propranolol, atenolol, and carvedilol 1
• For COPD patients, bisoprolol is specifically preferred due to superior beta-1 selectivity 1, 3

Dosing Approach

• Start with low doses and titrate gradually 3
• For metoprolol: consider smaller doses three times daily rather than larger doses twice daily to avoid higher peak plasma levels in patients with bronchospastic concerns 2
• Target heart rate reduction to 55-60 bpm if tolerated 5, 6

Mechanism of Benefit in Angina

Beta-blockers reduce myocardial oxygen demand through multiple mechanisms 1, 7:

• Decrease heart rate, which reduces myocardial oxygen consumption and increases diastolic filling time for coronary perfusion 1
• Reduce myocardial contractility and systolic blood pressure 1
• Blunt responses to exertion and stress 1
• Improve exercise capacity and reduce frequency of anginal attacks 5, 7

Critical Safety Warnings

Never Abruptly Discontinue

Abrupt withdrawal can cause severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias. 2

• When discontinuing, taper gradually over 1-2 weeks with careful monitoring 2
• If angina worsens during tapering, reinstate beta-blocker promptly 2
• This risk exists even in patients treated only for hypertension who may have unrecognized coronary disease 2

Heart Failure Considerations

Beta-blockers can precipitate heart failure initially but are beneficial long-term in compensated heart failure. 1

• Avoid in acute decompensated heart failure 1
• Strongly recommended before discharge in patients with compensated heart failure or LV systolic dysfunction for secondary prevention 1
• Greatest risk of precipitating heart failure is at treatment initiation, even with small doses 1, 6

Monitoring During Treatment

• Monitor heart rate and rhythm regularly 2
• In COPD patients, monitor specifically for wheezing, increased dyspnea, lengthening of expiration phase, increased sputum production 3
• If bronchospasm develops: increase inhaled beta-2 agonist therapy, temporarily reduce beta-blocker dose, or discontinue only if clearly necessary 3
• Watch for symptomatic bradycardia or hypotension 1, 2

Evidence Quality Note

The ACC/AHA guidelines provide Class IB recommendation for beta-blockers in unstable angina/NSTEMI 1, with oral administration preferred over IV in most cases based on contemporary evidence showing increased risk with aggressive early IV beta-blockade in hemodynamically compromised patients 1. The 2018 expert consensus specifically addresses the COPD concern, clarifying that cardioselective agents are safe and beneficial 1.