There were 879 eligible patients for this study. We excluded 36 patients because of incomplete data, inaccessibility, and lack of consent to answer the questions by telephone. Finally, the study was conducted on 843 patients; 449 women (53.4%) and 394 (46.7%) men. The mean age of the participants was 57.2 ± 13.6 years.

The number of patients with a previous revascularization history was 229 (≈27.2%), including 183 post-PCI patients (≈21.7%), 25 post-CABG patients (≈3%), and 21 patients with a history of both PCI and CABG (≈2.5%). The prevalence of underlying diseases was 62.2% for HTN, 27.2% for DM, 24.9% for dyslipidemia, and 5.6% for HF. In this study, 48 people (5.7%) were current cigarette smokers, and 47 (5.6%) were previous cigarette smokers.

At the beginning of the study, only 50 patients (5.9%) had received two doses of COVID-19 vaccination, and 38 people (4.5%) had been vaccinated with the first dose. Totally, 154 patients (18.3%) were admitted to a hospital due to COVID-19. The mean duration of the days after COVID-19 was about 383 ± 19 days.

The prevalence of dyspnea a year after COVID-19 was about 41.6% (351 patients); the frequency of mild, moderate, and severe dyspnea was estimated at 254 (30.1%), 56 (6.6%), and 41 (4.9%), respectively. The prevalence of different functional classes was I (411, 48.8%), II (348, 41.3%), III (47, 5.6%), and IV (37, 4.4%). Patients with a history of admission due to COVID-19 had a higher functional class than outpatients (P = 0.001). Women had more activity limitations (considering their functional class) than men after a year of COVID-19 recovery (P = 0.003) (Table 1).

At the end of the study, 407 patients (48.3%) reported no differences in regard to their dyspnea before and after a year following COVID-19. On the other hand, 157 patients (18.6%) reported worsening of their dyspnea, and interestingly, dyspnea was alleviated in 279 patients (33.1%). There were no differences between dyspnea scores before and after a year of COVID-19 based on the 10-score scale (P = 0.408). There was also no significant difference between the severity of dyspnea before and after a year of COVID-19 (P = 0.494).

Among the admitted ones due to COVID-19, 76 patients (49.4%) reported no differences between their dyspnea before and after a year following COVID-19; however, 55 patients (35.7%) reported that their dyspnea worsened after a year following COVID-19, and 23 patients (14.9%) reported improvement of their symptoms (P < 0.001). On the other hand, among patients not admitted due to COVID-19, 331 participants (48%) reported no differences between their baseline and follow-up dyspnea. However, 256 patients (37.2%) reported alleviation of their dyspnea, and 102 patients (14.8%) reported worsening of their symptoms (P < 0.001) (Table 2).

In hypertensive patients, the prevalence of dyspnea development was significantly higher than in non-hypertensives (P = 0.013). Patients with CAD experienced more worsening dyspnea than patients without CAD (P = 0.042). There was no association between dyspnea differences and any other cardiovascular risk factors, including age (P = 0.130), DM (P = 0.975), smoking (P = 0.438), and HLP (P = 0.446) (Table 2).

A year after COVID-19, 432 patients (51.2%) reported suffering from exertional dyspnea. Among patients admitted to the hospital, more cases (91 patients, 21.1%) reported DOE compared with those managed in outpatient settings (63 patients, 15.3%) (P = 0.033). Women reported more DOE than men (P = 0.032). There was also no association between DOE and any of the cardiovascular risk factors, including age (P = 0.197), HTN (P = 0.570), DM (P = 0.938), smoking (P = 0.876), HLP (P = 0.301), and CAD (P = 0.395) (Table 3).

After a year, 85 patients (10.1%) reported orthopnea. Among hospitalized patients, 26 patients (16.9%) had orthopnea, and among outpatient ones, 59 cases (8.6%) suffered from orthopnea after a year following COVID-19 (P = 0.004). The prevalence of orthopnea among women (56, 12.5%) was higher in comparison to men (29, 7.4%) (P = 0.016). There was no association between orthopnea and any of the cardiovascular risk factors, including age (P = 0.88), HTN (P = 0.639), DM (P = 0.609), smoking (P = 0.111), HLP (P = 0.793), and CAD (P = 0.156) (Table 3).

The prevalence of PND was 14.2% (120 patients) after one year following the infection. There was no meaningful association between PND and hospitalization (P = 0.610), gender (P = 0.694), age (P = 0.305), HTN (P = 0.478), DM (P = 0.825), smoking (P = 0.117), HLP (P = 0.649), and CAD (P = 0.321) (Table 3).

After one year, the prevalence of CP was 229 (27.1%). Among these, 66 patients (7.8%) reported cardiac CP, 163 patients (19.3%) had non-cardiac CP, and 614 cases (72.8%) reported no CP. The prevalence of cardiac and non-cardiac CP among hospitalized patients was 16.2% (25 patients) and 24.7% (38 patients), respectively. Among non-hospitalized patients, 41 (6%) reported cardiac CP, and 125 patients (18.1%) had non-cardiac CP (P < 0.001). There was no association between CP and sex (P = 0.875), age (P = 0.749), HTN (P = 0.176), DM (P = 0.702), smoking (P = 0.198), HLP (P = 0.865), and CAD (P = 0.233) (Table 4).

The prevalence of fatigue and palpitations was about 329 (39%) and 92 (10.9%) after a year of COVID-19. Patients with hyperlipidemia had more palpitations than others (P = 0.04). There was no association between fatigue or palpitations and hospitalization, sex, age, HTN, DM, smoking, and CAD (Table 4).

After a one-year follow-up of the COVID-19 patients, 54 cases (6.4%) showed MACE, including 44 ACS (5.2%), five hospitalizations due to heart failure (0.6%), four cerebrovascular accidents (0.5%), and one cardiac death (0.1%). The prevalence of MACE was higher in hospitalized patients (20, 13%) than in outpatients (34, 4.9%) (P = 0.001). Hypertensive cases had more incidence of MACE after a year of COVID-19 than non-hypertensives (P < 0.001). In patients with hyperlipidemia, 23 people (11%) reported MACE, while the prevalence of MACE in non-hyperlipidemic patients was 31 (4.9%) (P = 0.003). Patients with a history of previous revascularization had more MACE (P = 0.002). The prevalence of MACE in current and former smokers was 7 (14.6%) and 5 (10.6%). Although, 42 non-smokers (5.6%) had MACE after a year of COVID-19 (P = 0.049) (Table 4).