The median and interquartile age of the study subjects equaled 64.0 [53.0; 72.0] years. Considering gender distribution, 45% (n = 59) of the study participants were men and 55% (n = 73) were women.

AH was the most common CNCDs. It was observed in 90% of cases, with similar rates reported for the group receiving optimal (group 1) and non-optimal (group 2) therapies (89 and 93%, respectively, as shown in Table 1). Obesity was detected in 46% of study participants. Interestingly, patients receiving non-optimal therapy had obesity in 55% cases, and this value is significantly higher than the one confirmed for the group receiving optimal therapy (34% at p < 0.05). T2DM was diagnosed in 27%, CHD—in 15%, CHF—in 20% of patients. Oncology was found in 12% of patients. AF was detected in 8%, MI—in 8%, a history of stroke—in 10%, CKD—in 6%, COPD—in 3%, and bronchial asthma—in 5% of cases. As to the diseases listed above, there were no statistically significant intergroup differences revealed (Table 1).

One CD was present in 25% of patients. Meanwhile, it is worth noting that the majority of patients receiving an optimal therapy had one CD (p = 0.0005). Two or three CDs were observed in 51% of patients, and there were some differences identified: 59% in the optimal therapy group and 40% in the optimal therapy group (p = 0.03). Four concomitant diseases and more were revealed in 20% of patients, with no statistically significant intergroup differences identified.

Half of the surveyed patients (50%) reported health deterioration during the pandemic. Group 1 complained of worsening health in 40% of cases (n = 23), and group 2—in 58% of cases (n = 43, p = 0.035, as shown in Table 2).

Among patients receiving prehospital therapy, almost half of the responders (46%, n = 62) required adjustment of their basic therapy. Such a need was two times more common among group 2 patients (58%, n = 43) as compared to group 1 patients (33%, n = 19, p = 0.0065).

During an analysis of the actual period of therapy adjustment made for all treated CNCD patients, it turned out that half of all patients in the two groups (52%, n = 67) had their therapy adjusted before the start of the pandemic, i.e., more than a year before, 18% (n = 23) of patients—within the previous 6 months, 21% (n = 27)—6–12 months before, and 4% (n = 6) did not require therapy adjustment at all. The period of therapy adjustment in both study groups was 4 [3; 4] months, with no statistically significant intergroup difference demonstrated (p = 0.69). Similar results were obtained for the last doctor’s appointment (Table 2).

The need for inpatient care was recognized by 16% of the respondents (n = 21). There were 12% (n = 7) of patients requiring care in the inpatient setting in group 1 and 19% (n = 14)—in group 2 (p = 0.342).

Subjectively, reduced access to medical care was noted by 42% of the respondents (n = 55). This problem was experienced by 33% (n = 19) of group 1 patients and 49% (n = 36) of group 2 patients (p = 0.066). In 73% of cases (n = 40), the reasons for not receiving medical care were the unavailability of the healthcare professional needed and failure to make an appointment. Only 24% (n = 13) of patients explained their limited access to healthcare services by medical institutions reprofiling.

The proportion of patients who considered their treatment sufficient was quite high (78%, n = 102). It was similar in both groups, as this opinion shared 83% of patients (n = 45) in group 1 and 78% of patients (n = 57) in group 2 (p = 0.61).

Remarkably, only 12% (n = 15) of patients receiving treatment decided to discontinue their therapy during COVID-19 pandemic on their own. These were mainly group 2 patients (11 out of 15). There were 7% (n = 4) of patients who stopped the prescribed therapy in group 1 and 15% (n = 11)—in group 2 (p = 0.263).

The reasons for therapy discontinuation included worsening financial status and an increase in treatment costs. These answers were given by 66% of the respondents (n = 7). There were only two individuals who had a fear of going to the pharmacy because of the risk of contracting the virus (p = 0.268, Table 2).

The therapies received by the patients at the pre-hospitalization stage were analyzed. This analysis revealed that group 1 received angiotensin-converting enzyme inhibitors (ACE inhibitors), beta-blockers (BB), calcium channel blockers, and statins more often as compared to group 2 (Table 3).

The clinical characteristics of COVID-19 course were compared. This comparison confirmed that the rates of certain complications, such as cytokine storm, acute kidney injury, sepsis, and infective toxic shock, were higher among group 2 than among group 1 patients (Table 4).

The intensity of oxygen therapy was higher in group 2 as compared to group 1. The requirement for high-flow oxygenation and mechanical ventilation was higher among group 2 than among group 1 patients (Table 4).

Referring to the primary endpoint, in-hospital mortality was significantly higher among group 2 patients as compared to group 1 patients (21% versus 2%, p = 0.005, as shown in Table 4). As to the secondary endpoints, group 2 patients (non-optimal therapy) were found to have a significantly longer period of ICU stay as compared to group 1 patients (optimal therapy) (0 [0; 6] versus 0 [0; 0] days, p < 0.001). Moreover, group 2 patients had a longer hospital stay than group 1 patients (10 [8; 14] versus 8 [7; 11] days, p = 0.002, as shown in Table 4).