Can the cold pressor test predict future cardiovascular events in patients without demonstrated ischemic heart disease by SPECT?

Objective: To assess whether a cold pressor test (CPT) could help identify patients at a high risk of cardiovascular events in a population without known coronary artery disease (CAD) with a normal myocardial perfusion scintigraphy (MPS).

Methods: Our population consisted of 870 patients with a mean age of 59.3years with several CAD risk factors, having been referred for an MPS. The CPT was performed between the third day and fifth day after the MPS.

Results: The CPT was positive in 38.2% of the patients. After a mean 40-month follow-up, the patients were contacted to check for cardiac death, non-fatal myocardial infarction, and myocardial revascularization procedures. The event-free survival rates were 98.1% and 90.4% after a negative or positive CPT, respectively (p=0.0001). The positive CPT group exhibited a fourfold increased risk of CV events. All CV events in the negative CPT group occurred after a 30-month follow-up. The risk of CV events was 4.5 times higher in diabetic patients.

Conclusion: A positive CPT in patients with a negative MPS could help identify a subgroup of patients at a higher risk of developing symptomatic CAD.

Practice Implications: Our results suggest that after a normal post-exercise MPS, patients should undergo a CPT.