Clinical Phenotypes of Giant Cell Arteritis: Insights into Complications and Survival Outcomes.

Background: Giant cell arteritis (GCA) is a heterogeneous disease with diverse clinical presentations and varying degrees of severity. This study aimed to assess the incidence of 3 clinical subsets in GCA and analyze associated severe complications and survival rates. By identifying distinct clinical patterns, the goal is to customize treatment approaches and minimize severe complications during follow-up. Methods: This retrospective study classified clinical manifestations of GCA into 3 major phenotypes based on the reason for consultation: i) cranial, ii) extracranial, and iii) occult GCA. These groups were analyzed and compared for acute complications, including severe ischemic complications, "true" occlusive disease, and late complications such as aortic aneurysm. Survival data were also collected during follow-up. Results: Visual disturbances were more common in the cranial GCA group compared to other subsets (P < .001). Blindness and stroke showed a clinically relevant trend, although statistical differences were not significant between the cranial GCA groups. Limb claudication was significantly more prevalent in the extracranial subset compared to the cranial or occult GCA subsets (12% vs. 2.6% vs. 0% respectively). Severe ischemic complications and true occlusive disease were more frequent in the cranial GCA groups (60%, P=.005 and 40%, P=1.64 respectively). Regarding mortality, there were no statistically significant differences in survival among the different clinical subsets. However, the occult GCA subset showed a trend towards a higher prevalence of deaths, both overall and specifically due to GCA. Conclusion: Clinical subsets in GCA present distinct complications and survival outcomes, with the cranial subset showing a higher incidence of severe ischemic events and the occult subset associated with delayed diagnosis and increased mortality. Recognizing these subsets is crucial for tailored treatment approaches and improving patient prognosis. Further prospective studies are needed to refine diagnostic and therapeutic strategies.