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Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries
Talle, Mohammed Abdullahi. 2023. Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries. Unpublished doctoral dissertation. Stellenbosch : Stellenbosch University...
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| Language: | English |
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Stellenbosch : Stellenbosch University
2023
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| _version_ | 1867613987049308160 |
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| access_status_str | Open Access |
| author | Talle, Mohammed Abdullahi |
| author2 | Herbst, Philip G |
| author_browse | Herbst, Philip G Talle, Mohammed Abdullahi |
| author_facet | Herbst, Philip G Talle, Mohammed Abdullahi |
| author_sort | Talle, Mohammed Abdullahi |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Talle, Mohammed Abdullahi. 2023. Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries. Unpublished doctoral dissertation. Stellenbosch : Stellenbosch University [online]. Available at: https://scholar.sun.ac.za/items/a4a35df7-78bb-4527-ace6-9bbbe0f6fb48 |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/129335 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:44:52.037Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2023 |
| publishDateRange | 2023 |
| publishDateSort | 2023 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/129335 Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries Talle, Mohammed Abdullahi Herbst, Philip G Doubell, Anton F. Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medicine: Cardiology. Myocardial infarction Hypertension -- Complications Cardiovascular system -- Diseases Heart -- Magnetic resonance imaging UCTD Talle, Mohammed Abdullahi. 2023. Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries. Unpublished doctoral dissertation. Stellenbosch : Stellenbosch University [online]. Available at: https://scholar.sun.ac.za/items/a4a35df7-78bb-4527-ace6-9bbbe0f6fb48 Thesis (PhD)--Stellenbosch University, 2023. ENGLISH ABSTRACT: Hypertensive crisis is associated with an increased risk of adverse cardiac events with, raised cardiac troponin and altered cardiac morphology and function identified as specific risk factors. In addition, myocardial fibrosis, prevalent in hypertension and hypertensive crisis, provides a substrate for ventricular arrhythmia and sudden cardiac death. We assessed cardiac morphology, function, and myocardial tissue characteristics using cardiovascular magnetic resonance imaging (CMR) in patients with hypertensive crisis and a subgroup with positive troponin and unobstructed coronary arteries (myocardial injury and type 2 myocardial infarction). The CMR imaging protocol included steady state free precession (SSFP) based cine imaging, T2-weighted short tau inversion recovery (STIR), gadolinium contrast studies, and multi-parametric mapping [native T1, T2, and extracellular volume fraction (ECV)]. Imaging and serum biomarkers were compared between hypertensive urgency and hypertensive emergency, and their diagnostic utility were assessed for hypertensive emergency, left ventricular hypertrophy (LVH), and myocardial injury or type 2 myocardial infarction. The hypertensive crisis cohort was relatively young (age 48±13 years, 57% male), and 78% had a hypertensive emergency. Acute cardiac complications (acute pulmonary oedema and myocardial infarction) occurred in 66% of the cohort, while neurological complications occurred in 34%. Cardiac troponin, N-terminal prohormone of brain natriuretic peptide, and lactate dehydrogenase (LDH) were higher in hypertensive emergency, and myocardial injury without the criteria for myocardial infarction occurred in more than two-thirds of the cohort. LDH demonstrated excellent diagnostic utility in discriminating hypertensive emergency from hypertensive urgency. Left ventricular hypertrophy, systolic dysfunction, and late gadolinium enhancement (LGE) were more prevalent in the hypertensive emergency group than in hypertensive urgency. Increased STIR signal and T2 mapping, suggesting myocardial oedema, was demonstrated in the hypertensive emergency group and in patients with LVH. Among the group with a hypertensive emergency, LV mass correlated better with native T1 time than with T2 time suggesting that myocardial fibrosis may be contributing to increased native T1 time. The group with myocardial injury and type 2 myocardial infarction had higher T2 times and ECV, suggesting myocardial oedema. Compared to controls, a trend for a higher prevalence of LGE, driven mainly by infarct-pattern LGE, was observed in the group with myocardial injury and type 2 myocardial infarction. In addition to signifying the presence of replacement fibrosis, the LGE observed in the context of increased T2 and ECV may be due to myocardial necrosis. Our findings have important implications in the clinical evaluation, management, risk stratification, and prognostication of patients with hypertensive crisis. Higher levels of serum cardiac biomarkers in the hypertensive emergency group indicate an increased risk of adverse cardiac events. Similarly, the high prevalence of altered cardiac structure and function may contribute to the increased risk of adverse events associated with hypertensive crisis, including arrhythmic sudden cardiac death. The combination of CMR biomarkers provide evidence of myocardial fibrosis and oedema, allowing for non-invasive characterization of myocardial tissue architecture in hypertensive crisis. The CMR imaging biomarkers may serve as therapeutic targets or surrogate endpoint measures in clinical trials. Longitudinal outcome studies are required to determine the prognostic utility of these imaging biomarkers in hypertensive crisis. AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar. Doctoral 2023-09-19T13:44:50Z 2024-02-20T07:57:22Z 2023-09-19T13:44:50Z 2024-02-20T07:57:22Z 2023-09 Thesis https://scholar.sun.ac.za/handle/10019.1/129335 en Stellenbosch University xii, 183 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Myocardial infarction Hypertension -- Complications Cardiovascular system -- Diseases Heart -- Magnetic resonance imaging UCTD Talle, Mohammed Abdullahi Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries |
| title | Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries |
| title_full | Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries |
| title_fullStr | Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries |
| title_full_unstemmed | Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries |
| title_short | Myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis, raised cardiac troponin and normal or unobstructed epicardial coronary arteries |
| title_sort | myocardial tissue characterization using cardiac magnetic resonance in patients with acute hypertensive crisis raised cardiac troponin and normal or unobstructed epicardial coronary arteries |
| topic | Myocardial infarction Hypertension -- Complications Cardiovascular system -- Diseases Heart -- Magnetic resonance imaging UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/129335 |
| work_keys_str_mv | AT tallemohammedabdullahi myocardialtissuecharacterizationusingcardiacmagneticresonanceinpatientswithacutehypertensivecrisisraisedcardiactroponinandnormalorunobstructedepicardialcoronaryarteries |