Digital ischaemia during cooling is independently related to nailfold capillaroscopic pattern in patients with Raynaud's phenomenon

Objective. The aim of the study was to assess the association between plethysmographically measured vasospasms during stepwise cooling and recovery, as an index for digital ischaemia, and nailfold capillaroscopic pattern (NCP) severity in patients with primary or secondary RP, including SSc. Methods. In 381 consecutive patients with suspected RP without a history of digital ulcers, NCP (assessed by widefield videocapillaroscopy), fingertip photoelectric plethysmography during cooling and recovery and clinical characteristics were analysed. NCPs were graded as follows: normal, non-specific, early and active. The mean ischaemic time was defined as the mean time of perfusion loss during cooling and recovery of five fingers. Results. In the patients with loss of perfusion during cooling and recovery, the NCP was normal in 152, non-specific in 96, early in 61 and active in 39 patients. The mean ischaemic time was positively associated with the severity of NCP, with P < 0.05 for each two- or three-grade increase and independent of underlying SSc. The difference was most pronounced during recovery. Conclusion. We demonstrate that the degree of vasospasm and ischaemia provoked by stepwise cooling and recovery are positively associated with NCP in patients with RP of different aetiologies and without a history of digital ulcers.