Back to Authors

Brown, Robert D.

Mayo Clinic

Mayo Clinic

Citations 50

The effect of 2 years COVID-19 pandemic on myocardial infarction and stroke admissions: nationwide registry study, sex differences and mortality
Šedová, Petra , Brown, Robert D., Ostadal, P, Lichter, Myrna, Kala, Petr , Ostadal, P, Vrablı́k, Michal , Jarkovský, Jiří , Lichter, M, Tichopád, Aleš , Mikulík, Robert

European Heart Journal | October 28, 2024 | Volume: 45 | Issue: Supplement_1 | Pages: No page available

10.1093/eurheartj/ehae666.3593 Get It

Abstract Background Throughout the COVID-19 pandemic many countries reported a decline in myocardial infarction (MI) and stroke admissions. Factors leading to the decline remain uncertain. Purpose In this nationwide study spanning the first two years of the COVID-19 pandemic we evaluated the changes in MI and stroke admissions as the effect of pandemic intensity and nationwide lockdown. We also investigated sex and age differences. We benefited from the fact that the Czech Republic had both, the lowest and one of the highest COVID-19 incidence. Methods We compared the first (March 1, 2020, to February 28, 2021) and the second (March 1, 2021, to February 28, 2022) pandemic years overall and during the COVID-19 waves with the preceding year (March 1, 2019, to February 28, 2020). The occurrence of MI and stroke, patient characteristics, and mortality data were obtained from two nationwide registers covering every hospitalization and every death in the Czech Republic. Results During the first and second pandemic year as compared to the preceding year there were 13,856 and 14,123 vs 15,499 MI admissions, representing a -10,6% (p<0.001) and -8,9% (p<0.001) decline; and 23,194 and 23,231 vs 25,046 stroke admissions, representing a -7.4% (p<0.001) and -7.2% (p<0.001) decline respectively. The significant decline appeared in both MI and stroke in all COVID-19 waves (spring 2020, spring 2021, autumn 2020/winter 2021, -autumn 2021/winter 2022). The greatest MI hospitalization decline (-16%) occurred during the first strict national lock down, during the first COVID-19 wave (spring 2020), the pandemic wave with the lowest COVID-19 incidence. Both, MI and stroke admissions reversed to pre-pandemic numbers during the summer (2020, 2021) when most lockdown restrictions were lifted. The decline in MI was greater in women than in men during both the first (-11.8%, -10%; p<0.001) and second (-10.8%, -7.9%; p<0.001) pandemic years, also for stroke in women greater than in men during the first (-9%, -5.9%; p<0.001) and second (-9.7%, -4.8%; p<0.001) pandemic years. The 30-day all-cause mortality in patients with MI was higher during the first (10.6%; p<0.001) but not the second (9.6%; p=0.34) pandemic year as compared to the preceding year (9.3%), whereas the 30-day mortality in patients with stroke remained unchanged. Conclusions There was a decline in both MI and stroke admissions during the first two years of the pandemic, but such decline was not related to COVID-19 incidence. The greatest reduction in both, MI and stroke admissions, appeared during the first lockdown in the first COVID-19 wave (spring 2020), the period of the lowest COVID-19 incidence. Moreover, the decline in MI and stroke admissions was greater in women. This highlights potential sex differences in health effect. Health authorities should be aware of these findings, in order to adapt their message and restriction measures in case of future major epidemics.Myocardial infarction casesStroke cases
Abstract 106: Validation Of The Unruptured Intracranial Aneurysm Treatment Score (UIATS) to Guide Management of Unruptured Intracranial Aneurysms
Etminan, Nima , Brown, Robert D., Torner, James C., Raymond, Jean , Raabe, Andreas , Abdulazim, Amr , Connolly, E. Sander , Pasqualin, A., Rüfenacht, Daniel A. , LeRoux, Peter D. , McDougall, Cameron M. , Hänggi, Daniel , Macdonald, R. Loch , Investigators, UIATS, Beseoglu, Kerim , Juvela, Seppo , Morita, Akio , Derdeyn, Colin P. , Mocco, J , Korja, Miikka , Steinmetz, Helmuth , Lanzino, Giuseppe , Vajkoczy, Peter , Rinkel, Gabriël J.E. , Investigators, UIATS

Stroke | March 20, 2022 | Volume: 46 | Issue: suppl_1 | Pages: No page available

10.1161/str.46.suppl_1.106 Get It

Objective: We previously derived the Unruptured Intracranial Aneurysm Treatment Score (UIATS), designed using a multidisciplinary consensus approach among neurovascular specialists from diverse geographic and practice backgrounds. Here, we report on the development and validation of the final version of UIATS. Method: An international, multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 (39 panel members and 30 blinded external reviewers) specialists in the research and treatment of UIAs was convened. A web survey-based Delphi consensus process consisting of 7 rounds was utilized to rate numerous features of potential relevance in the assessment and treatment of UIAs and to develop the UIATS. Mean ratings were repeatedly used to determine statistical weight for each factor and then transformed into corresponding scores for every item to create the UIATS. For internal and blinded external validation, 30 representative cases of patients with UIAs were used to test the level of agreement (5 point Likert Scale) with treatment recommendations based on the UIATS. Results: The final UIATS system was designed in three domains (patient-, aneurysm - and treatment-related), comprising 13 different categories and 29 different features (Figure 1). Mean agreement based on Likert scores (5 indicating strong agreement and 1 indicating strong disagreement) was 4·2 for both reviewer cohorts, whereas mean agreement per case was 4·2 (panel members) and 4·5 (external reviewers) (p=0·017, Mann-Whitney-U Test). Conclusion: The final version of UIATS system was internally and externally validated by a large multidisciplinary group of neurovascular specialists, which suggests that the UIATS reflects contemporary decision-making regarding management of a patient with an UIA. The UIATS may aid clinicians in deciding on the appropriate management for an UIA.
Abstract WP79: Choice Of Treatment And Effect On Hemorrhage Rates Of Unruptured Intracranial Aneurysms
Torner, James C., Zhang, Jie , Piepgras, David G., Meissner, Irene, Brown, Robert D., Investigators, ISUIA, Huston, John , Investigators, ISUIA

Stroke | July 3, 2021 | Volume: 44 | Issue: suppl_1 | Pages: No page available

10.1161/str.44.suppl_1.awp79 Get It

INTRODUCTION: The decision regarding whether to perform an interventional procedure as a strategy to prevent hemorrhage of an unruptured intracranial aneurysm (UIA) requires careful consideration of procedural risk and the UIA natural history. No randomized trial data are available. The International Study of Unruptured Intracranial Aneurysms (ISUIA) included a prospective cohort, examining hemorrhage risk and treatment risk. Hypothesis: The purpose of this analysis was to compare the factors related to treatment selection and determination of the number of hemorrhages prevented. Methods: Patients were allocated into the initial treatment and untreated cohorts based upon observation or treatment practices in 61 centers from 1991-1998. 1691 patients were in the observational cohort, 471 were in the endovascular cohort and 1917 patients were in the surgical cohort. The cohorts were followed for a median follow-up of 9.2 years. Outcomes were determined prospectively and with central review. The data were grouped together and analyzed to determine treatment decisions. A Cox proportional hazards model predicting hemorrhage developed in the observation cohort and was applied to the surgery and endovascular cohorts across the follow-up period. Results: Significant baseline variable differences between treated and observed patients were aneurysm size, symptoms, age, prior SAH group, geographical region, treatment percentage, aneurysm daughter sacs or multiple lobes, and history of hypertension, smoking and myocardial infarction. Aneurysm site and family history were not significant. Site, size, and aspirin use were significant predictors of hemorrhage. Long-term the predicted hemorrhage rates were 6.7% at 5 years and 8.0% at 10 years in the surgery group and 8.1% and 9.6% for the endovascular group, respectively. For comparison the rates in the observed cohort were 4.1% and 4.8%, respectively. Conclusions: Decisions for treatment are influenced by patient characteristics such as age and medical history, aneurysm characteristics such as size and morphology and center and regional practices. Patients in the treated cohorts were at moderately increased risk for hemorrhage compared to those in the observed cohort.
Abstract TMP27: Aneurysm Morphology And Prediction Of Rupture In Unruptured Intracranial Aneurysms
Brown, Robert D., Torner, James C., Raghavan, Madhavan L. , Piepgras, David G., Meissner, Irene, Huston, John , Investigators, International Study of Unruptured Intracranial Aneurysms, Torner, James C. , Capuano, Ana Werneck , Mocco, J , Investigators, International Study of Unruptured Intracranial Aneurysms

Stroke | July 3, 2021 | Volume: 44 | Issue: suppl_1 | Pages: No page available

10.1161/str.44.suppl_1.atmp27 Get It

Introduction: There is ongoing debate regarding the rupture risk of an unruptured intracranial aneurysm (UIA), and the predictors of rupture. Hypothesis: There are aneurysm morphology characteristics which predict rupture in patients with an UIA. The purpose of this analysis was to assess for such characteristics utilizing the International Study of Unruptured Intracranial Aneurysms (ISUIA) cohort. Methods: Patients were entered prospectively at 61 centers. Patients must have had at least one UIA, which may or may not have been symptomatic. Patients were followed for a median of 9 years and all potential hemorrhages were carefully adjudicated. A case-control design was used. The cases were 57 patients with aneurysmal rupture during followup for whom detailed radiology data were available from arteriography. Controls were 198 size- (+/- 2 mm maximum diameter) and location- (parent artery) matched patients without rupture during followup. Numerous aneurysm morphology characteristics were assessed on arteriogram review. Multivariable condition logistic regression modeling was performed. Results: A total of 57 cases and 198 controls were included. Most (76%) of the 255 cases were women, and 20% had a prior history of SAH from some other aneurysm. There were no differences between cases and controls in aneurysm maximum diameter, aneurysm location, patient age, gender, reason for presentation, or prior medical history. Multivariate analysis identified that only perpendicular height of the aneurysm--the measurement of the aneurysm height at a perpendicular to the center of the aneurysm neck to the aneurysm dome-was an independent predictor of aneurysm rupture. Aspect ratio, size ratio, parent vessel diameter, presence of daughter sac, and aneurysm angle were not independent predictors of rupture. Conclusions: After controlling for aneurysm size and location, the aneurysm perpendicular height remained a predictor of UIA rupture during long-term followup. The assessment of perpendicular height may be helpful in clinical practice, in addition to the other key predictors of UIA rupture, aneurysm maximum diameter and location. Further investigation into the use of perpendicular height as a predictor of rupture in patients with UIA is indicated.
Presymptomatic Screening for Intracranial Aneurysms in Patients with Autosomal Dominant Polycystic Kidney Disease
Sanchis, Irina M., Shukoor, Shehbaz, Irazabal, María V. , Madsen, Charles D. , Hogan, Marie C. , Zoghby, Ziad , Harris, Peter C. , Brown, Robert D., Torres, Vicente E. , El-Zoghby, Ziad , Harris, Peter C , Torres, Vicente E , Irazabal, Maria V , Hogan, Marie C , Chebib, Fouad T. , Huston, John

Clinical Journal of the American Society of Nephrology | July 30, 2019 | Volume: 14 | Issue: 8 | Pages: 1151-1160

10.2215/cjn.14691218 Get It

Background and objectives Intracranial aneurysm rupture is the most devastating complication of autosomal dominant polycystic kidney disease. Whether selective or widespread intracranial aneurysm screening is indicated remains controversial. Design, setting, participants & measurements Records of 3010 patients with autosomal dominant polycystic kidney disease evaluated at the Mayo Clinic between 1989 and 2017 were reviewed. Those who had presymptomatic magnetic resonance angiography screening were included. Results Ninety-four intracranial aneurysms were diagnosed in 75 of 812 (9%) patients who underwent magnetic resonance angiography screening. Sex, age, race, and genotype were similar in the groups with and without aneurysms; hypertension and history of smoking were more frequent in the aneurysm group. Twenty-nine percent of patients with aneurysms compared with 11% of those without aneurysms had a family history of subarachnoid hemorrhage ( P <0.001). Most aneurysms were small (median diameter =4 mm; range, 2–12 mm); 85% were in the anterior circulation. During a total imaging follow-up of 469 patient-years, de novo intracranial aneurysms were detected in five patients; eight intracranial aneurysms grew (median =2 mm; range, 1–3 mm). During a total clinical follow-up of 668 patient-years, seven patients had preemptive clipping or coil embolization; no intracranial aneurysms ruptured. During a total clinical follow-up of 4783 patient-years in 737 patients with no intracranial aneurysm detected on the first magnetic resonance angiography screening, two patients had an intracranial aneurysm rupture (0.04 per 100 person-years; 95% confidence interval, 0 to 0.10). The rate of intracranial aneurysm rupture in large clinical trials of autosomal dominant polycystic kidney disease was 0.04 per 100 patient-years (95% confidence interval, 0.01 to 0.06). Conclusions Intracranial aneurysms were detected by presymptomatic screening in 9% of patients with autosomal dominant polycystic kidney disease, more frequently in those with familial history of subarachnoid hemorrhage, hypertension, or smoking. None of the patients with and two of the patients without aneurysm detection on screening suffered aneurysmal ruptures. The overall rupture rate in our autosomal dominant polycystic kidney disease cohort was approximately five times higher than that in the general population.
Relationship between procedural characteristics and cerebrovascular events after transcatheter aortic valve replacement
Slusser, Joshua P. , Lennon, Ryan J. , Brown, Robert D., Greason, Kevin L. , Holmes, David R. , Lennon, Ryan, Goel, Kashish , Nkomo, Vuyisile T.

Open Heart | October 7, 2018 | Volume: 5 | Issue: 2 | Pages: e000816

10.1136/openhrt-2018-000816 Get It

Objectives The objective was to assess the impact of procedural characteristics on risk of stroke or transient ischaemic attack (TIA) after transcatheter aortic valve replacement (TAVR). Methods We included 370 consecutive patients who underwent balloon-expandable TAVR from 1 November 2008 to 30 June 2014. Procedural characteristics that may be associated with stroke/TIA were assessed. The primary outcome was stroke/TIA at 30 days. A propensity score was constructed using a logistic regression model with 29 parameters. Cox proportional hazards models were used with a propensity score covariate. Results Mean age was 80.9±7.9 years and mean Society of Thoracic Surgeons score was 8.3±5.0. The total number of balloon dilations ranged from 2 to 7. Out of 370 patients, 13 patients (3.5%) suffered stroke/TIA in the first 30 days after TAVR. In univariate analysis, postdeployment balloon dilation (PD) (HR 3.8, 95% CI 1.24 to 11.61; p=0.02) and emergent cardiopulmonary bypass (CPB) (HR 9.66, 95% CI 2.66 to 35.15; p<0.001) were significantly associated with 30-day stroke/TIA. In the multivariable Cox-proportional hazards model, PD (HR 4.95, 95% CI 1.02 to 24.03; p=0.04) and emergent CPB (HR 7.15, 95% CI 1.39 to 36.89; p=0.02) were independently associated with increased risk of 30-day stroke/TIA after adjusting for propensity score, total number of balloon dilations and periprosthetic regurgitation. Conclusion Postdilation as compared with total number of dilations, and emergent CPB were independently associated with increased risk of clinical neurological events in the first 30 days after TAVR. Reduction in balloon postdilation with appropriate valve sizing may reduce the risk of stroke or TIA after TAVR.
Accuracy of detecting enlargement of aneurysms using different MRI modalities and measurement protocols
Nakagawa, Daichi , Nagahama, Yasunori , Policeni, Bruno , Raghavan, Madhavan L. , Dillard, Seth, Schumacher, Anna , Sarathy, Srivats, Wilson, Saul, Allan, Lauren , Woo, Henry H. , Cloft, Harry J. , Torner, James C., Brown, Robert D., Torner, James C. , Dlouhy, Brian J , Huston, John , Wintermark, Max , Hasan, David

Journal of Neurosurgery | March 9, 2018 | Volume: 130 | Issue: 2 | Pages: 559-565

10.3171/2017.9.jns171811 Get It

OBJECTIVEAneurysm growth is considered predictive of future rupture of intracranial aneurysms. However, how accurately neuroradiologists can reliably detect incremental aneurysm growth using clinical MRI is still unknown. The purpose of this study was to assess the agreement rate of detecting aneurysm enlargement employing generally used MRI modalities.METHODSThree silicone flow phantom models, each with 8 aneurysms of various sizes at different sites, were used in this study. The aneurysm models were identical except for an incremental increase in the sizes of the 8 aneurysms, which ranged from 0.4 mm to 2 mm. The phantoms were imaged on 1.5-T and 3-T MRI units with both time-of-flight (TOF) and contrast-enhanced MR angiography. Three independent expert neuroradiologists measured the aneurysms in a blinded manner using different measurement approaches. The individual and agreement detection rates of aneurysm enlargement among the 3 experts were calculated.RESULTSThe mean detection rate of any increase in any aneurysmal dimension was 95.7%. The detection rates of the 3 observers (observers A, B, and C) were 98.0%, 96.6%, and 92.7%, respectively (p = 0.22). The detection rates of each MRI modality were 91.3% using 1.5-T TOF, 97.2% using 1.5-T with Gd, 95.8% using 3.0-T TOF, and 97.2% using 3.0-T with Gd (p = 0.31). On the other hand, the mean detection rate for aneurysm enlargement was 54.8%. Specifically, the detection rates of observers A, B, and C were 49.0%, 46.1%, and 66.7%, respectively (p = 0.009). As the incremental enlargement value increased, the detection rate for aneurysm enlargement increased. The use of 1.5-T Gd improved the detection rate for small incremental enlargement (e.g., 0.4–1 mm) of the aneurysm (p = 0.04). The location of the aneurysm also affected the detection rate for aneurysm enlargement (p < 0.0001).CONCLUSIONSThe detection rate and interobserver agreement were very high for aneurysm enlargement of 0.4–2 mm. The detection rate for at least 1 increase in any aneurysm dimension did not depend on the choice of MRI modality or measurement protocol. Use of Gd improved the accuracy of measurement. Aneurysm location may influence the accuracy of detecting enlargement.
Dual antiplatelet therapy in aneurysmal subarachnoid hemorrhage: association with reduced risk of clinical vasospasm and delayed cerebral ischemia
Nagahama, Yasunori , Allan, Lauren , Nakagawa, Daichi , Starke, Robert M. , Chalouhi, Nohra , Brown, Robert D., Derdeyn, Colin P. , Leira, Enrique C. , Chimowitz, Marc I. , Torner, James C., Hasan, David , Torner, James C. , Zanaty, Mario , Jabbour, Pascal , Broderick, Joseph P. , Derdeyn, Colin P

Journal of Neurosurgery | November 3, 2017 | Volume: 129 | Issue: 3 | Pages: 702-710

10.3171/2017.5.jns17831 Get It

OBJECTIVE Clinical vasospasm and delayed cerebral ischemia (DCI) are devastating complications of aneurysmal subarachnoid hemorrhage (aSAH). Several theories involving platelet activation have been postulated as potential explanations of the development of clinical vasospasm and DCI. However, the effects of dual antiplatelet therapy (DAPT; aspirin and clopidogrel) on clinical vasospasm and DCI have not been previously investigated. The objective of this study was to evaluate the effects of DAPT on clinical vasospasm and DCI in aSAH patients. METHODS Analysis of patients treated for aSAH during the period from July 2009 to April 2014 was performed in a single-institution retrospective study. Patients were divided into 2 groups: patients who underwent stent-assisted coiling or placement of flow diverters requiring DAPT (DAPT group) and patients who underwent coiling only without DAPT (control group). The frequency of symptomatic clinical vasospasm and DCI and of hemorrhagic complications was compared between the 2 groups, utilizing univariate and multivariate logistic regression. RESULTS Of 312 aSAH patients considered for this study, 161 met the criteria for inclusion and were included in the analysis (85 patients in the DAPT group and 76 patients in the control group). The risks of clinical vasospasm (OR 0.244, CI 95% 0.097–0.615, p = 0.003) and DCI (OR 0.056, CI 95% 0.01–0.318, p = 0.001) were significantly lower in patients receiving DAPT. The rates of hemorrhagic complications associated with placement of external ventricular drains and ventriculoperitoneal shunts were similar in both groups (4% vs 2%, p = 0.9). CONCLUSIONS The use of DAPT was associated with a lower risk of clinical vasospasm and DCI in patients treated for aSAH, without an increased risk of hemorrhagic complications.
Aneurysm Morphology and Prediction of Rupture: An International Study of Unruptured Intracranial Aneurysms Analysis
Brown, Robert D., Torner, James C., Fargen, Kyle M , Raghavan, Madhavan L. , Piepgras, David G., Meissner, Irene, Investigators, on behalf of the International Study of Unruptured Intracranial Aneurysms, Torner, James C. , Mocco, J , Capuano, Ana Werneck , Huston, John , Investigators, on behalf of the International Study of Unruptured Intracranial Aneurysms, Fargen, Kyle M

Neurosurgery | May 24, 2017 | Volume: 82 | Issue: 4 | Pages: 491-496

10.1093/neuros/nyx226 Get It

Abstract BACKGROUND There are conflicting data between natural history studies suggesting a very low risk of rupture for small, unruptured intracranial aneurysms and retrospective studies that have identified a much higher frequency of small, ruptured aneurysms than expected. OBJECTIVE To use the prospective International Study of Unruptured Intracranial Aneurysms cohort to identify morphological characteristics predictive of unruptured intracranial aneurysm rupture. METHODS A case-control design was used to analyze morphological characteristics associated with aneurysm rupture in the International Study of Unruptured Intracranial Aneurysms database. Fifty-seven patients with ruptured aneurysms during follow-up were matched (by size and location) with 198 patients with unruptured intracranial aneurysms without rupture during follow-up. Twelve morphological metrics were measured from cerebral angiograms in a blinded fashion. RESULTS Perpendicular height ( P = .008) and size ratio (ratio of maximum diameter to the parent vessel diameter; P = .01) were predictors of aneurysm rupture on univariate analysis. Aspect ratio, daughter sacs, multiple lobes, aneurysm angle, neck diameter, parent vessel diameter, and calculated aneurysm volume were not statistically significant predictors of rupture. On multivariate analysis, perpendicular height was the only significant predictor of rupture (Chi-square 7.1, P -value .008). CONCLUSION This study underscores the importance of other morphological factors, such as perpendicular height and size ratio, that may influence unruptured intracranial aneurysm rupture risk in addition to greatest diameter and anterior vs posterior location.
Differential Sex Response to Aspirin in Decreasing Aneurysm Rupture in Humans and Mice
Chalouhi, Nohra , Starke, Robert M. , Correa, Tatiana , Brown, Robert D., Torner, James C., Hasan, David , Torner, James C. , Zanaty, Mario, Hasan, David M, Jabbour, Pascal , Zanaty, Mario

Hypertension | June 14, 2016 | Volume: 68 | Issue: 2 | Pages: 411-417

10.1161/hypertensionaha.116.07515 Get It

We previously found that aspirin decreases the risk of cerebral aneurysm rupture in humans. We aim to assess whether a sex differential exists in the response of human cerebral aneurysms to aspirin and confirm these observations in a mouse model of cerebral aneurysm. A nested case–control analysis from the International Study of Unruptured Intracranial Aneurysms was performed to assess whether a sex differential exists in the response of human cerebral aneurysms to aspirin. A series of experiments were subsequently performed in a mouse model of cerebral aneurysms. Aneurysms were induced with hypertension and elastase injection into mice basal cisterns. We found that aspirin decreased the risk of aneurysm rupture more significantly in men than in women in the International Study of Unruptured Intracranial Aneurysms. In mice, aspirin and cyclooxygenase-2 inhibitor did not affect cerebral aneurysm formation but significantly decreased the incidence of rupture. The incidence of rupture was significantly lower in male versus female mice on aspirin. Gene expression analysis from cerebral arteries showed higher 15-hydroxyprostaglandin dehydrogenase levels in male mice. The rate of cerebral aneurysm rupture was similar in male mice receiving aspirin and 15-hydroxyprostaglandin dehydrogenase inhibitor compared with females receiving aspirin and 15-hydroxyprostaglandin dehydrogenase agonist, signaling a reversal of the sex-differential response to aspirin. Aspirin decreases aneurysm rupture in human and mice, in part through cyclooxygenase-2 pathways. Evidence from animal and human studies suggests a consistent differential effect by sex. 15-Hydroxyprostaglandin dehydrogenase activation in females reduces the incidence of rupture and eliminates the sex-differential response to aspirin.