Cold pressor test and paradoxical blood pressure reduction in light chain amyloidosis.

BACKGROUND

Patients with AL amyloidosis present sustained paradoxical vasodilation in response to sympathetic stimulation by cold pressor test (CPT). The clinical relevance is unknown.

METHODS

Peripheral and central systolic (SBP) and diastolic blood pressure (DBP) were measured at 3 min (end of CPT) and at 6 min, before and 12 months after treatment initiation in 113 treatment-naïve AL amyloidosis patients. Ten healthy volunteers were assessed at baseline. All-cause and cardiovascular mortality were recorded.

RESULTS

Percentage reductions in central SBP and peripheral DBP at 6 min [AL vs controls: %CSBP6min (mean, SD) 0.7 ± 8.44 vs 7.57 ± 5.59; %DBP6min (mean, SD) 0.64 ± 8.91 vs 14 ± 9.11; p < 0.01 for both] were associated with all-cause and cardiovascular death (%CSBP6min HR = 0.945 and HR = 0.946 respectively; %DBP6min HR = 0.949 and HR = 0.916 respectively; p < 0.05 for all) after adjustment for disease-related risk factors. %CSBP6min provided incremental value over Mayo stage and was associated with neurological and cardiac dysfunction and myocardial infiltration. At 12 months, %CSBP6min further decreased in patients with earlier poor hematologic treatment response.

CONCLUSIONS

%CSBP6min, a noninvasive, readily available marker, was associated with cardiac dysfunction, poor survival, and its further post-treatment reduction was associated with hematologic response.