You are a clinical decision support assistant. A 55-year-old male patient presents with chest pain, shortness of breath, and elevated troponin levels. He has a history of hypertension and type 2 diabetes. Based on current guidelines, provide a concise differential diagnosis and recommend the next best diagnostic step. Limit your response to 150 words and cite relevant clinical guidelines if applicable.

Context/Constraint:

• Use current clinical knowledge and evidence-based guidelines.
• Limit response length.
• Must include diagnostic reasoning.

Example Output:

The symptoms and elevated troponin suggest acute coronary syndrome (ACS), but differential includes pulmonary embolism and aortic dissection. The next best step is an ECG and urgent cardiology consult. Follow-up with coronary angiography if ECG confirms STEMI. Reference: ACC/AHA Guidelines for ACS (2021).