Table 1.

Summary of the studies concerning the association between hypertension and long-COVID

Author Country [Reference]	Recruitment	Design	Number and population	Median follow-up (days)	Outcome	Significance on hypertension	Note
Xie et al. US [39]	VA national healthcare database	Retrospective cohort study	153,760 COVID-19 patients (mean age 61.4 years, 89.0% male), two sets of control cohorts with 5,637,647 and 5,859,411 individuals	347	Risk and 1-year burden of incident cardiovascular outcomes	Increased risk of cardiovascular diseases at a post-acute phase was independent of pre-existing hypertension	> 30 days after infection, COVID-19 patients were at increased risk of incident cardiovascular diseases. The risk/burden was evident even in those who were not hospitalized, and was increased in those who were hospitalized and admitted to the intensive care unit
Tleyjeh et al. Saudi Arabia [37]	Inpatients	Prospective cohort study, single center	222 COVID-19 inpatients (mean age 52.5 years, 77.0% male)	122	Predictors associated with persistent symptoms and non-return to baseline health status	Pre-existing hypertension was associated with persistent symptoms, but not with non-return	56.3% of patients complained of persistent symptoms, mainly shortness of breath (40.1%), cough (27.5%), and fatigue (22.7%)
Blomberg et al. Norway [38]	Home-isolated patients and inpatients	Prospective cohort study	312 patients with COVID-19 (247 home-isolated and 65 hospitalized (median age 61 years, 49% male)	Followed at 6 ± 1 month	Persistent symptoms 6 months after initial COVID-19	Pre-existing hypertension was associated with increased fatigue score but not after adjustment	61% of patients had persistent symptoms at 6 months, including fatigue (37%), difficulty concentrating (26%), and disturbed smell or taste (25%)
Al-Aly et al. US [41]	VA national healthcare database	Retrospective cohort study	73,435 patients with COVID-19 who did not hospitalize and survived for ≥ 30 days (median age 60.7 years, 87.9% male). 4,990,835 outpatients who did not have COVID-19 as control	126	Hazards and excess burden of long-COVID at 6 months based on a high dimensional approach	COVID-19 survivors had excess burdens of hypertension	> 30 days after infection, COVID-19 patients were at higher risk of death and were more likely to use healthcare resources
Cohen et al. US [42]	2 clinical research databases	Retrospective cohort study	87,337 of 133,366 matched patients aged ≥ 65 years (mean age 76.9 years, 43.6% male) with 3 control groups by propensity score	56	Persistent and new sequelae of long-COVID at ≥ 21 days after a diagnosis, determined with ICD-10 codes, and hazards and excess sequelae risk for the 120 days after acute infection	The risk difference and hazard ratio of hypertension as clinical sequelae were increased as compared with control cohorts	32% of COVID-19 patients developed ≥ 1 sequela during the post-acute phase. The risks for most clinical sequelae including hypertension were higher in patients who needed hospital admission than in those who did not
Daugherty et al. US [43]	3 clinical research databases	Retrospective cohort study	193,113 of 266,586 matched patients aged 18–65 years (mean age 41.7 years, 47.6% male) with 3 control groups by propensity score	95	Same as above	Same as above	14% of COVID-19 patients developed ≥ 1 new type of clinical sequelae requiring medical care. The risk for incident sequelae including hypertension increased with age, pre-existing conditions, and admission to hospital for COVID-19

COVID-19 coronavirus disease 2019, long-COVID post-acute sequelae of COVID-19, ICD-10 International Classification of Diseases, 10th revision, VA the US Department of Veterans Affairs