A 62-year-old male smoker with a 40 pack-year history presents with progressive dyspnea, chronic cough, and sputum production for the past 3 years. Spirometry shows FEV₁/FVC ratio of 0.58 with FEV₁ 45% predicted. Chest X-ray reveals hyperinflation with flattened diaphragms and a prominent vascular pattern in the lower lung zones. He denies acute exacerbation symptoms. What is the most appropriate next step in management?