Monitorización de la presión arterial en las primeras 24 horas del ictus, estudio diferencial según el tipo de ictus y de su valor pronóstico precoz

Abstract

The evaluation and management of blood pressure (BP) is of paramount importance in the acute phase of stroke. Ambulatory blood pressure monitoring (ABPM) is used in the study and evaluation of hypertension, but its value in the acute phase of stroke has hardly been studied. This study aims to investigate the BP obtained by Blood Pressure Monitoring for 24 hours (BPM24h) on the first day of hospital admission for stroke, using ABPM equipment, analyzing their possible differences according to the type of stroke and its early prognostic value. Material and methods: Observational, longitudinal, prospective cohort study on stroke of less than 24 hours of evolution admitted for 4 consecutive years in the Internal Medicine Service of the General Hospital La Mancha Centro at Alcázar de San Juan who underwent BPM24h on the first day of admission and the modified Rankin scale (mRS) was determined on the seventh day. The study has been approved by the Hospital's Scientific Research Ethics Committee and informed consent has been obtained from the participants. Multivariate linear and binary logistic regression has been performed using the propensity score (PS) obtained as the probabilities of positive response in a multinomial regression model with the polytomous dependent variable type of stroke and the independent variables for control confounding bias sex, hypertension, diabetes mellitus (DM), dyslipidemia, heart failure (HF), National Institute of Health Stroke Scale (NIHSS) score at admission, intercurrent disease, age, previous stroke, and antiplatelet therapy. Results: A total of 499 strokes have been recruited, with a median age of 74 years (interquartile range –IQR– 67 to 79 years), 282 (56.5%) are men, 297 (59.5%) are hypertensive, 183 (36.7%) are diabetic and 60 (12%) with dyslipidaemia. The median body mass index is 25.8 kg/m2 (IQR 23.8 to 29.0 kg/m2). 100 patients (20.0%) had had a previous stroke, 25 (5%) had a previous myocardial infarction, 68 (13.6%) had atrial fibrillation, 21 (4.2%) had HF, and 117 (23.6%) some other intercurrent illness. The median NIHSS score on admission is 6 (IQR 3 to 13) points. The distribution by type of stroke is 197 (37.5%) lacunar strokes, 99 (19.8%) cardioembolic, 155 (31.1%) atherothrombotic, and 58 (11.6%) hemorrhagic. 392 (78.9%) cases of good prognosis at 7 days have been found by mRS, of which 234 (47.1%) are independent (mRS 0-1) and 190 (32, 2%) have mild or moderate dependence (mRS 2-3); and 105 (21.1%) have poor prognosis, of which 55 (11.1%) have moderate-severe or severe dependence (mRS 4-6 ) and 48 (9.7%) die (mRS 7). Medians systolic BP (SBP) are 134 (IQR 119 to 147) mmHg for lacunar stroke, 138 (IQR 124 to 156) mmHg for cardioembolic, 145 (IQR 127 to 160) mmHg for atherothrombotic and 144 (IQR 129 to 161) mmHg for hemorrhagic stroke. The medians of diastolic BP (DBP) are 71 (IQR 64 to 78.5) mmHg in lacunar stroke, 70 (IQR 62 to 78) mmHg in cardioembolic, 74 (IQR 67 to 84) mmHg in atherothrombotic and 80 (IQR 70 to 93) in hemorrhagic stroke. In the multivariate analysis adjusted for the PS, no significant differences were observed in the SBP values (p>0.200). Significant differences are observed in DBP values (p=0.006). In the six multiple comparisons two to two of the four types of stroke, significant differences were found in DBP between hemorrhagic-lacunar (mean difference 4.5 mmHg; 95% confidence interval –CI– 0.5 to 8.4 mmHg; p=0.028), hemorrhagic-cardioembolic (7.5 mmHg; 95% CI 3.3 to 11.6 mmHg; p<0.001) and hemorrhagic-atherothrombotic (4.4 mmHg; 95% CI 0.7 to 8.1 mmHg; p=0.022). In the analysis with multivariate linear regression adjusted for the PS, no statistically significant differences were observed in the day/night SBP ratio (p>0.200) or DBP ratio (p>0.200) or in the circadian SBP patterns (p>0.200). The circadian patterns of DBP being different (p=0.001) fundamentally at the expense of a decrease in the dipping pattern in atherothrombotic (41.3%) and haemorrhagic (43.4%) strokes versus lacunar (51.8%) and cardioembolic strokes. (50.6%). The median SBP in the poor prognosis group is 148 (IQR 132 to 168) mmHg and in the good prognosis group 136 (IQR 21 to 150) mmHg. The median DBP in the poor prognosis group is 74 (IQR 65 to 83.5) mmHg and in the good prognosis group 73 (IQR 65 to 81) mmHg. In the analysis with multivariate binary logistic regression adjusted by the PS, the values of SBP (odds ratio –OR– 1.01; 95% CI 1.00 to 1.02; p=0.111) or DBP (OR 1.00; 95% CI 0.98 to 1.02; p>0.200) on day 1 are not associated with a poor prognosis. A relationship with the prognosis is found in the night/day SBP ratio (multiplied by 100: OR 1.05; 95% CI 1.01 to 1.09; p=0.022) and night/day DBP ratio (multiplied by 100: OR 1.04; 95% CI 1.00 to 1.07; p=0.045). Also related to prognosis is the fall on day 7 compared to day 1 in both SBP (OR 0.97; 95% CI 0.95 to 0.99; p=0.002) and DBP (OR 0.93; 95% CI 0.90 to 0.97; p <0.001). Conclusions: In determining the BP obtained by BPM24h on day 1 of hospital admission for stroke, there are no differences in SBP between the four types of stroke (lacunar, cardioembolic, atherothrombotic and haemorrhagic), but there is in DBP, with hemorrhagic strokes showing the highest DBP, with no differences in the DBP of lacunar, cardioembolic and atherothrombotic strokes among themselves. There are no differences between the four types of stroke in the night/day SBP or DBP ratios, or circadian SBP patterns. The circadian DBP patterns are being different fundamentally at the expense of a decrease in the dipping pattern in atherothrombotic and hemorrhagic strokes. The SBP and DBP values on day 1 of admission for stroke are not related to the early prognosis at 7 days. The decrease in SBP and DBP from day 1 to day 7 of admission for stroke is related to a good early prognosis. Regarding the circadian patterns, the increase in the night/day SBP and DBP ratios on day 1 of admission for stroke are related to a poor early prognosis.