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Stroke prevalence is known to increase with age. Approximately 50% of acute ischemic stroke patients are aged between 70 and 89 years.
In this study, records of 770 ischemic stroke patients who were 70–89 years old were retrospectively examined (407 septuagenarians and 363 octogenarians). The demographics, comorbid conditions, ischemic stroke type, and stroke outcome for the two age groups were analyzed.
Comorbid hypertension, diabetes mellitus, and HbA1c levels of ≥6.5% more frequently occurred in septuagenarians than in octogenarians (80.6% versus 70.8%, p=0.002; 32.2% versus 21.8%, p=0.001; and 35% versus 23.2%, p=0.003, respectively), whereas atrial fibrillation was significantly higher in octogenarians (49.3% versus 41.5%, p=0.03). Hypercholesterolemia, previous stroke history, and antiaggregant and/or anticoagulant use were not significantly different between the two age groups. Based on the Oxfordshire Community Stroke Project classification, the most common stroke subtype in the septuagenarian group was a lacunar infarction and in the octogenarian group, it was a partial anterior circulation infarct. According to the Modified Ranking Score, the number of patients living independently was higher for septuagenarians (42.8% versus 27.8%, p<0.001).
The present findings indicate that the clinical characteristics of ischemic stroke differed between septuagenarians and octogenarians. Therefore, elderly stroke patients cannot be accepted as a homogeneous group. Because this is a hospital-based study, our findings need to be tested via additional epidemiological studies.
Global demographics reveal an aging population, and stroke prevalence is known to increase with age. In the USA, studies indicate that approximately 50% of acute ischemic stroke patients are aged between 70 and 89 years (1) and that in Europe, almost one-third of new ischemic strokes occur in patients aged 80 years or older (2). Patient number, however, is not the only factor influencing the management of stroke in the elderly. Elderly patients are typically excluded from clinical trials (3), creating a gap in available data. Furthermore, healthcare resources are often restricted, and symptoms are often undertreated (4) with increasing age (5).
Aging is a multivariate process as elderly patients of different age groups are likely to present varied stroke characteristics. Prior studies have investigated ischemic stroke patients using decade-by-decade classification scales over broad age groups (e.g., 50–90 years) (1) or via wide-ranging dual age segregation (e.g., >80 years versus <80 years and 65–84 years versus >85 years) (6,7). The current study seeks to affirm the relationship between stroke and age with a specific focus on two age groups: 70–79 years (septuagenarians) and 80–89 years (octogenarians). We aimed to identify variations in ischemic stroke presentation (specifically demographics, clinical characteristics, and outcomes) between septuagenarians and octogenarians to assist the age-targeted research of elderly stroke patients.
This study retrospectively reviews the medical records of 2,210 acute stroke patients. The Institutional Ethics Committee at Haseki Training and Research Hospital approved the study. Records cover January 2010–July 2013 for patients admitted to the inpatient neurology clinics of Haseki Training and Research Hospital. Stroke type was diagnosed with cranial computed tomography and diffusion-weighted magnetic resonance imaging. Patients with sinus vein thrombosis and hemorrhagic strokes were excluded (n=442). Of the remaining 1,768 ischemic stroke patients, 770 were aged between 70 and 89 years.
Data collected from 770 patients included demographics (age and sex), risks factors, stroke classification, and outcome. The analyzed clinical characteristics included hypertension (HT), diabetes mellitus (DM), atrial fibrillation (AF), hypercholesterolemia (total cholesterol level>200 mg/dL), glycated hemoglobin (HbA1c level≥6.5%), previous stroke, and antiaggregant (aspirin or clopidogrel) and/or anticoagulant (warfarin) use.
The determinations of HT and DM were based on prior antihypertensive and antidiabetic drug use. Patients with AF were identified via first electrocardiography (ECG) on admission and on available 24-h Holter monitor recordings. Holter monitoring reports accepted short-lasting (<30 s) irregular runs of supraventricular tachycardias as paroxysmal AF. An HbA1c cut-off point of 6.5% was selected according to the mean value for all septuagenarian and octogenarian patients included in this study. The stoke classification used the Oxford Community Stroke Project subtype categories: lacunar infarction (LACI), partial anterior circulation infarct (PACI), posterior circulation infarct, and total anterior circulation infarct (TACI) (8). Stroke outcomes were assigned a Modified Ranking Scale (MRS) on discharge (MRS≤2 represents independent living and MRS≥3 represents dependent living or death) (9).
This study used Statistical Package for the Social Sciences 15.0 (SPSS Inc., Chicago, IL, USA). For categorical variables, the number and percent values were used. Continuous variables were expressed as the mean and standard deviation. For comparisons between groups, the Mann–Whitney U test was used when the variables were not normally distributed, while the chi-square test was used for categorical variables. Predictors of dependent living were determined using the backward method of linear regression analysis. The regression model for this study was based on age, gender, HT, hypercholesterolemia, antiaggregant and/or anticoagulant use, and HbA1c levels of ≥6.5%. Statistical significance was accepted as p<0.05.
Of the 770 patients investigated, 407 were septuagenarians and 363 were octogenarians. The demographics of the septuagenarians and octogenarians include mean age of 74.5±2.9 and 84.6±3.9 years, respectively, (p≤0.001), and female-to-male ratios of 1.31 and 2.08, respectively, (p=0.002). The following clinical characteristics were more frequent in the septuagenarian group: HT (80.6% versus 70.8%, p=0.002), DM (32.2% versus 21.8%, p=0.001), and HbA1c levels of ≥6.5% (35% versus 23.2%, p=0.003). The percentage of AF was significantly higher in octogenarians (49.3 % versus 41.5%, p=0.03).
Summary statistics for hypercholesterolemia, previous stroke, antiaggregant and/or anticoagulant use are presented in Table 1. Differences in these clinical characteristics were not statistically significant between the two groups (p=0.72, p=0.77, and p=0.24, respectively). The stroke classification, as shown in Table 2, recorded a greater frequency of LACI (35.9%) in septuagenarians and of PACI (44.9%) in octogenarians (p<0.001).
Stroke outcome results are presented in Table 3. Dependent living and/or death (MRS≥3) were more frequent in octogenarians (52.7 vs. 72.2%, p<0.001). Values for previous stroke were higher in the dependent living group for both septuagenarians and octogenarians (p=0.02 and p=0.017, respectively), while the proportion of females and patients with HbA1c levels of ≥6.5% were higher only in the dependent living group for septuagenarians (p<0.001). Dependent and independent living was further assessed according to the stroke subtype: in the dependent living group, TACI was higher in septuagenarians, while PACI was higher in octogenarians (p<0.001 for both).
Results of the regression analysis for the demographic and clinical characteristics related to ischemic stroke are presented in Table 4. Age (>80 years), female gender, and HbA1c levels of ≥6.5% were assessed as significant predictors of dependent living or death (p<0.001, p=0.009, and p=0.003, respectively).
This study investigated differences in ischemic stroke demographics, clinical characteristics, classification, and outcomes between septuagenarians and octogenarians. The proportion of females to males was higher in both age groups, with the gender divide more prominent in octogenarians. This was not unexpected given that from a general demographic viewpoint, the lifespan of females is longer than that of males (10).
The first key variation in clinical ischemic stroke presentation between septuagenarians and octogenarians was related to DM and HT frequencies. Current literature confirms an association between DM and/or HT and decreased longevity (11). The frequencies of HT and DM in this study were found to be greater in septuagenarians than in octogenarians. This age-specific relationship may relate to the tendency of people with systemic disease to live shorter lives or experience their first stroke earlier in life.
In a recent study investigating ischemic stroke in patients aged 65–84 or ≥85 years, DM was greater in the 65–84-year age group; however, HT demonstrated no difference between the two age groups (7). Similarly, in a study assessing patients on a decade-by-decade scale for the age ranges <50 and >90 years, the results for DM were higher in septuagenarians than in octogenarians, but no variance was found for HT (1). While these results are a slight deviation from the findings of the current study, a publication by a team of cardiologists investigating only two age categories (70–79 and 80–89 years) reported figures similar to the present data, namely that HT and DM in septuagenarian and octogenarian stroke patients were both higher in the septuagenarian group (HT: 73.5 % versus 65.5% and DM: 33.4% versus 25.5%) (12). These studies provide strong evidence of the two potential risk factors demonstrating inconsistent presentation in elderly ischemic stroke patients.
Another key variation in the clinical presentation of ischemic stroke characteristics between septuagenarians and octogenarians is the frequency of AF. The results of the current study mirror the well-known positive correlation between age and AF (13). In a study of 535 patients using the age categories <80 and >80 years, AF frequencies were found to be 11% and 24.6%, respectively (6). The frequencies of AF in the current study for septuagenarians and octogenarians were 41.5% and 49.3%, respectively, (p=0.03). Similarly, a decade-by-decade assessment of ischemic stroke age-related characteristics reported AF percentages of 20.7% and 31.8% for septuagenarians and octogenarians, respectively (1). The reason for the higher frequency of AF in this study may be the inclusion of short-duration (<30 s) paroxysmal AF. The current study did not use an etiologic stroke classification; however, it is known that AF is the main cause of cardioembolic stroke. As such, it can be speculated that cardioembolic stroke is more common in octogenarians than in septuagenarians.
Comparing dependent living and non-dependent living in relation to clinical characteristics, previous stroke had a negative effect in both septuagenarians and octogenarians, while HbA1c levels of ≥6.5% had a negative effect only in septuagenarians. HbA1c levels of ≥6.5%, gender, and age were also found to be predictors of stoke outcome. This result for HbA1c levels of ≥6.5% is supported by prior studies, where the functional outcome for HbA1c levels of >6% was predicted to deteriorate 12 months after stroke (14).
The limitations of this study include the following: 1) smoking status, which is a significant vascular risk factor, was not recorded for patients and 2) etiologic classification was not used. As such, predictions regarding the etiology of index stroke cannot be confirmed, and epidemiologic studies are needed to support our findings.
In conclusion, the current study successfully analyzed variations in ischemic stroke presentation between septuagenarians and octogenarians. Differences in both vascular clinical characteristics and outcomes were found. Most notably, comorbid HT, DM, and HbA1c levels of ≥6.5% were more frequent in septuagenarians, while frequencies of AF were higher in octogenarians. These results support the theory that elderly stroke patients are not a homogeneous group and therefore require age-specific considerations. Stroke management targeted toward the elderly needs to be planned in future studies.
Ethics Committee Approval: Ethics committee approval was received for this study from the ethics committee of Haseki Training and Research Hospital.
Informed Consent: Since this was a retrospective study based on the screening of medical records, an informed consent could not be obtained.
Peer-review: Externally peer-reviewed.
Author Contributions: Concept – B.B.; Design – B.B., S.G.; Supervision – F.Ö., Ö.Ç.; Resources – F.B.B., A.M., S.G.; Materials – H.A.; Data Collection and/or Processing – B.B., S.G.; Analysis and/or Interpretation – A.M., F.B.B., Ö.Ç.; Literature Search – B.B., S.G.; Writing Manuscript – B.B.; Critical Review – Ö.Ç., F.Ö., H.A.; Other – F.B.B., A.M.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: The authors declared that this study has received no financial support.