{
  "abstract": "Introduction Raynaud’s phenomenon (RP) is characterized by episodic cold-induced vasospasm of digital arteries. Secondary RP is associated with underlying systemic diseases, particularly systemic sclerosis (SSc), where it affects virtually all patients. Unlike primary RP, secondary RP in SSc involves progressive structural vascular damage that may fundamentally alter the pattern and severity of cold-induced vasospasm. Photo-electric plethysmography (PPG) provides objective assessment of digital artery perfusion by directly measuring blood volume changes in proper palmar digital arteries (PPDA), offering advantages over thermography or laser Doppler techniques that primarily assess superficial capillary flow. We hypothesized that structural vascular changes in secondary RP result in prolonged ischemic recovery and altered temperature thresholds for vasospasm onset compared to primary RP.Material and Methods Retrospective analysis consisting of 262 patients (64.9% female, median age of 46 years (IQR 30-57)) who underwent nailfold capillaroscopy (NCP) and standardized cooling in our vascular laboratory between 2008 until 2025. Hands were cooled from 33°C to 6°C in steps of 3°C in water, after which the hands recovered at room air temperature. Perfusion was measured by PPG during this procedure. Participants were categorized into the primary RP-group when autoantibodies and NCP were negative. The remaining participants were categorized into the secondary group.Results Most participants (n=195, 74.4%) underwent cooling procedures as part of routine clinical testing, while a smaller group (n=67, 25.6%) was tested in study-context. Secondary RP was observed in 146 participants (55.7%), and of those 67 (26%) had no classifiable underlying disease, 33 (23%) were diagnosed with SSc and 16 (6%) had a diagnosis of Sjogren’s disease. The remaining had miscellaneous underlying diseases. Secondary RP showed prolonged ischemic time in minutes during rewarming in the middle finger (3.0, IQR:0.0-10.0), p=0.024), ring finger (1.0, IQR:1.0-8.0, p=0.023) and little finger (1.0, IQR:0.0-7.0, p=0.012). A borderline difference was seen for ischemic time during rewarming in the thumb (p=0.050). No significant differences in temperature thresholds or ischemic time from cooling to rewarming were observed. A preliminary subgroup analysis shows prolonged ischemic time in SSc during both the cooling procedure and rewarming period.Conclusions In secondary RP, cold-induced ischemic events lead to prolonged ischemic recovery times during rewarming in the fingers when compared to primary RP. Preliminary data suggests prolonged ischemic time in SSc-patients which is in line with clinical observations of aggravated cyanosis and increased digital ulcer risk in SSc. These objective PPG-findings may provide measurable endpoints that could guide therapeutic interventions aimed at reducing ischemic duration in secondary RP.Abstract P.201 Figure 1",
  "authors": [
    {
      "affiliations": [
        "University Medical Centre Groningen - Department of Internal Medicine, Groningen, The Netherlands"
      ],
      "name": "Jesse Cappelle"
    },
    {
      "affiliations": [
        "University Medical Centre Groningen - Department of Internal Medicine, Groningen, The Netherlands"
      ],
      "name": "Saskia C Van De Zande"
    },
    {
      "affiliations": [
        "University Medical Centre Groningen - Department of Internal Medicine, Groningen, The Netherlands"
      ],
      "name": "Anne I Van Gessel"
    },
    {
      "affiliations": [
        "University Medical Centre Groningen - Department of Rheumatology and Clinical Immunology, Groningen, The Netherlands"
      ],
      "name": "Alja J Stel"
    },
    {
      "affiliations": [
        "University Medical Centre Groningen - Department of Internal Medicine, Groningen, The Netherlands"
      ],
      "name": "Arie M Van Roon"
    },
    {
      "affiliations": [
        "University Medical Centre Groningen - Department of Internal Medicine, Groningen, The Netherlands"
      ],
      "name": "Udo DJ Mulder"
    }
  ],
  "title": "P.201 Photoelectric plethysmography reveals distinct digital artery recovery patterns in secondary Raynaud’s phenomenon: a 262-patient study with systemic sclerosis subanalysis",
  "uid": "0f2d2f61-6b47-50ff-9ab6-0e1c859eba2c"
}