Baseline characteristics
Between 2008 and 2020, out of 10,297 patients diagnosed with MMD, 296 patients (2.9%) experienced an event in 2021, and 175 patients (1.7%) died. When comparing the non-event group to the event group, the proportion of individuals aged 60 and over was significantly higher in the event group (non-event group vs event group, 31.1% vs 48.0%; p<0.001), as was the proportion of males (33.4% vs 42.2%; p=0.002). The percentage of patients with a BMI<18.5 (2.9% vs 6.1%; p=0.004) and those with a history of previous stroke (57.9% vs 77.7%; p<0.001) were also significantly higher in the event group. Conversely, the rates of undergoing RS (8.8% vs 3.4%; p<0.001) and receiving a COVID-19 vaccination (91.3% vs 63.5%; p<0.001) were significantly lower in the event group, whereas the incidence of COVID-19 infection (1.1% vs 2.7%; p=0.013) was significantly higher in the event group (Table 1).
When comparing the non-mortality group to the mortality group, the proportions of individuals aged 60 and over (32.0% vs 58.9%; p<0.001), males (33.5% vs 44.6%; p=0.002), those with a BMI<18.5 (2.8% vs 9.1%; p<0.001), and those with a history of previous stroke (58.1% vs 78.9%; p<0.001) were significantly higher in the mortality group. Additionally, the incidence of COVID-19 infection was higher in the mortality group (1.2% vs 2.9%; p=0.037). Conversely, the rates of undergoing RS (8.8% vs 3.4%; p=0.005) and receiving a COVID-19 vaccination (91.2% vs 54.9%; p<0.001) were significantly lower in the mortality group (Table 1).
Risk factors evaluation for occurrence of events
In the evaluation of risk factors for event occurrence through univariable analysis, being over the age of 40, having a BMI below 18.5, a history of previous stroke, and COVID-19 infection were identified as significant risk factors. Conversely, undergoing RS and receiving vaccinations emerged as significant preventive factors. Subsequent multivariable analysis, incorporating variables significant in the univariable analysis, revealed that ages 50-59 (OR 3.29 [95% CI 1.18-9.12]; p=0.022) and 60 or above (OR 5.20 [95% CI 1.89-14.29]; p=0.001), a BMI below 18.5 (OR 2.00 [95% CI 1.18-3.41]; p=0.011), a history of previous stroke (OR 1.96 [95% CI 1.47-2.60]; p<0.001), and COVID-19 infection (OR 2.28 [95% CI 1.07-4.87]; p=0.034) were significant risk factors. Being female (OR 0.64 [95% CI 0.50-0.82]; p=0.011), undergoing RS (OR 0.38 [95% CI 0.21-0.70]; p<0.001), and vaccination (OR 0.17 [95% CI 0.13-0.22]; p<0.001) were significant preventive factors against event occurrence (Table 2).
Risk factors evaluation for occurrence of mortality
In the univariable analysis, factors identified as significant included being aged 50 or above, having a BMI below 18.5, a FBS level of 126 or higher, a history of previous stroke, COVID-19 infection, undergoing RS, and receiving vaccinations. The multivariable analysis further identified being aged 60 or above (OR 7.09 [95% CI 1.69-29.81]; p=0.008), having a BMI below 18.5 (OR 3.87 [95% CI 1.79-8.38]; p=0.001), and a history of previous stroke (OR 1.74 [95% CI 1.19-2.54]; p=0.004) as independent risk factors for mortality. Conversely, being female (OR 0.52 [95% CI 0.38-0.72]; p<0.001), undergoing RS (OR 0.41 [95% CI 0.24-0.89]; p=0.022), and vaccination (OR 0.12 [95% CI 0.09-0.16]; p<0.001) were independently preventive factors against the occurrence of mortality (Table 3).
Risk and effectiveness evaluation according to types of vaccines
The impact of different vaccine types on the occurrence of events, mortality, and COVID-19 infections was analyzed. It was found that the Pfizer (OR 0.42 [95% CI] 0.31-0.59]; p<0.001) and Moderna vaccines (OR 0.45 [95% CI 0.30-0.67]; p<0.001) had a significantly higher preventive effect against the occurrence of events compared to the AstraZeneca vaccine. Similarly, for the prevention of mortality, the Pfizer (OR 0.34 [95% CI 0.22-0.52]; p<0.001) and Moderna vaccines (OR 0.30 [95% CI 0.17-0.55]; p<0.001) were significantly more effective compared to the AstraZeneca vaccine. Likewise, regarding the prevention of COVID-19 infections, the Pfizer (OR 0.62 [95% CI 0.41-0.96]; p=0.032) and Moderna vaccines (OR 0.33 [95% CI 0.18-0.36]; p=0.001) were found to have significantly higher efficacy compared to the AstraZeneca vaccine (Table4).