A new study presented at the European League Against Rheumatism Annual Congress ( EULAR 2014 ) has shown a significantly increased risk of myocardial infarction in patients with Sjögren's syndrome ( SjS ), particularly in the first year following diagnosis. There was also a trend towards an increased risk for stroke.
Sjögren's syndrome is an auto-immune inflammatory disease where the body's immune system attacks glands that secrete fluid, such as the tear and saliva glands. Inflammation within the glands reduces fluid production causing painful burning in the eyes, dry mouth, and sometimes dryness in the nasal passages, throat, vagina and skin.
Primary Sjögren's syndrome occurs in people with no other rheumatological disease; secondary Sjögren's syndrome occurs in people who have another rheumatological disease, most often systemic lupus erythematosus ( SLE ) and rheumatoid arthritis ( RA ).
The worldwide prevalence of primary Sjögren's syndrome has been estimated at about 0.2% of the adult population, and is thought to affect at least nine times as many women as men.
According to the principal investigator of the study, Antonio Aviña-Zubieta, at University of British Columbia, Vancouver, Canada, it is the acute inflammatory state in Sjögren's syndrome, particularly at the onset of the disease, which is likely to be the main driver for the increased risk of myocardial infarction and stroke.
This is the first general population-based cohort study comparing the relative risk of myocardial infarctions and strokes in patients with new Sjögren's syndrome with age, sex, and entry-matched controls.
The results support the role of inflammation in cardiovascular disease and the need for increased monitoring for coronary artery disease in all patients with this condition, in addition to proper management and modification of their cardiovascular risk factors to reduce the risk of a future myocardial infarction.
Looking first at the myocardial infarctions, out of 1,176 new cases with Sjögren's syndrome, 28 developed a first time heart attack, with an incident rate of 7.7 per 1,000 person-years. Among 11,879 non-SjS matched controls, 138 had a heart attack, with an incident rate of 3.5 per 1,000 person-years.
The results for the stroke cohorts showed that, among 1,195 with new Sjögren's syndrome, 19 developed a first-time stroke, with an incident rate of 5.1 per 1,000 person-years. Out of 11,983 non-SjS matched controls, 137 had a cerebrovascular event, with an incident rate of 3.4 per 1,000 person-years.
Compared with the age, sex and entry matched controls, the relative risks for myocardial infarction and stroke events were 2.2 and 1.5, respectively.
Adjusting for other relevant risk factors for cardiovascular disease including medications made no significant difference to the relative risk of patients with Sjögren's syndrome developing either myocardial infarctions 2.4 or stroke 1.6.
The risk of developing a myocardial infarction was highest within the first year following diagnosis of Sjögren's syndrome ( 3.6 times ), and persisted up to five years following the initial diagnosis. This trend was not seen for strokes.
This was a retrospective matched cohort study with new Sjögren's syndrome patients satisfying at least one of the following criteria: diagnosis of Sjögren's syndrome in adults on at least two visits at least two months apart and within a two-year period between 1996 and 2010 by a non-rheumatologist physician diagnosis of Sjögren's syndrome on at least one visit by a rheumatologist or from hospitalisation.
Incident myocardial infarction and stroke events were recorded based on hospitalisation or death certificate. To estimate relative risks, Sjögren's syndrome patients were compared with age-, sex- and entry time-matched comparison cohorts, adjusting for potential cardiovascular risk factors. Ten non-SjS controls matched by birth year, sex and calendar year of follow-up were selected from the general population for each case of Sjögren's syndrome. ( Xagena )
Source: European League Against Rheumatism ( EULAR ) Meeting, 2014