The angiographic characteristics of our patients pointed that the mean number of lesions were 3.18 and 4.6 in PCI and GABG group, respectively. With a less than 0.001 p-value, the CABG group had a considerably greater number of lesions than PCI group. The SYNTAX score I was 19.5 in the PCI group and 23.72 in the CABG group, which is significantly higher in the latter group with a 0.003 p-value. The Euroscore II was 1.71 in the CABG group. When comparing our results with the literature available we found accordance with the NOBLE, SYNTAX and Freedom trials as their SYNTAX score and number of lesions and Euro scores. Their SYNTAX score in PCI group was 22.5, 28.4, and 26.2, respectively, compared to 22.4, 29, and 26.1 in the CABG group. In the same trials, the mean number of lesions in the PCI group was 2, 4.3, and 5.65 compared to 2, 4.4, and 5.74 in the CABG group, respectively. The Euro scores in the CABG were 2, 3.8, and 2.8, respectively [7, 8]. With a mean value of 2.46, the number of stents used in the present research ranged from 1 to 5. The intraprocedural complications in the angiography were only in 2% of cases. These findings were comparable with the published trials, where the mean number of stents used in BEST trial , Freedom follow on study , and Gimbel et al.  study were 3.4, 3.4, and 1.71, respectively.
One of the major factors that affect the choice of the revascularization technique is the in-hospital stay. Comparing the CABG group to the PCI group, the hospital stay duration was noticeably longer in the CABG group (8.16 vs. 2.02 days; P < 0.001).
This finding comes in agreement with NOBLE trial that stated that the duration of indexed treatment admission in PCI group was 2 days compared to 9 days in CABG group (2 vs. 9 days; P < 0.001) . Moreover, the CARDIA trial also confirmed the median time spent in CABG was significantly longer than PCI, being 9 days for the earlier and 1 day for the latter, with a P-value less than 0.001 .
Other studies observed a longer duration stays such as LE MANS trial and Becher et al., where the LE MANS trial, pinpointed that the mean days of hospitalization was 6.8 and 12.04 days in the PCI and CABG group, respectively, with P-value = 0.0007. Becher et al. reported that the CABG group’s hospital stay was substantially longer than the PCI group’s (16.1 vs. 8.8 days; P < 0.0.5) .
In the present study, we compared the in-hospital MACE in both the PCI and the CABG group. The PCI group’s frequency of occurrence of in-hospital heart failure was 0% compared to 2% in the CABG group, while that of the renal impairment and myocardial infarction was 2% in both groups. Neither groups required revascularization, nor had in-hospital bleeding.
The CABG group had a higher frequency of cerebrovascular stroke as compared to that of the PCI group being 4% in the former group and 2% in the latter group but was not statistically significant.
This could be attributed to elder and seriously ill population that is considered appropriate to undergo CABG. The ascending aorta's formation of atheromatous fragments during hypo-perfusion and surgical manipulation are the two factors that contribute to the etiology of cerebrovascular stroke in CABG .
The handling of the aorta in cannulation, anastomosis, and cross‐clamping of a conduit could represent a risk for thromboembolic process, where most patients undergoing CABG suffer from atherosclerosis of the ascending aorta and surgical manipulation can lead to detachment of atheromatous plaques or calcified deposits, specifically during the aortic cross‐clamp placement or removal. Immediate postoperative causes of cerebrovascular stroke in CABG patients are mainly due to atrial fibrillation (POAF) before hospital discharge. Also, previous causes mentioned in the intraoperative period may still cause embolic clots which lead to stroke. Additionally, in the early postoperative period, anesthetic residual effects can prevent the detection of intraoperative strokes. Another potential factor is the low cardiac output syndrome, prolonged inotrope usage, and postoperative bleeding, which is linked to hypo-perfusion caused by hypovolemia and often anemia which raise the risk of cerebrovascular stroke in these patients .
Regarding the fatality rate although it was more in the CABG group (6%) than 2% only in the PCI group yet it was statistical insignificant, which could be explained by the higher risk the patients are subjected to during such a major invasive operation and it might have reached the significance threshold if the sample size was increased.
Hsu et al. investigated the in-hospital MACE and compared it in both the CABG and PCI groups. They demonstrated that the frequency of in-hospital death was higher among CABG group (20.5%) than the PCI group (5%). There was a higher occurrence of in-hospital cerebrovascular stroke in the CABG group than PCI group being 2.6% in the former and 0% in the latter group. The repeated revascularization was observed in 2.6% of CABG patients and none in the PCI group.
Hsu et al.  justified these findings by the differences in the study population, where the CABG group was at high surgical risk based on the Euro score classification, which rationalizes the relatively high rate of observed adverse events.
In accordance with our outcomes Prashanth et al. describes similar frequencies of in-hospital MACE, where the frequencies of in-hospital death, MI and revascularization of targeted vessel in PCI patients were 2%, 2.9%, and 0%, respectively, compared to our results 2%, 2%, and 0%, respectively .
The long-term follow-up care of MACE in this study revealed that 12.2% of PCI patients had heart failure compared to 6.4% in the CABG group; however, it was statistically insignificant. Wang et al. reported that the patients undergoing PCI and CABG had heart failure frequency of 1.8 and 1.94, respectively, in the follow-up study .
We assessed the mortality rates in long-term follow-up care among the PCI and CABG group, which was 10.2% and 4.3%, respectively. The updated Noble reported comparable data as the rate of mortality in both the PCI and CABG groups were 9%. They concluded that although mortality was similar, yet patients who received PCI had higher myocardial infarction rates and repetition of revascularization, and recommended improving the long-term outcomes by tailoring patient selection and optimization .
On the other hand, the Freedom follow on the study pinpointed that the PCI group’s long-term mortality was greater compared to the CABG group with 24.3% versus 18.3% stating that compared to PCI-DES, CABG continues to reduce all-cause mortality better. The better survival with CABG has been attributed in part to the increasing use of internal mammary grafts in these trials .
In the current study, no case of post-procedural myocardial infarction among both groups was observed. Similarly, the EXCEL trial, 5-year follow-up reported the primary composite rate of MI in PCI and CABG group to be 5.1% and 2.4%, respectively .
Moreover, the PRECOMBAT extended study reported comparable results with slightly higher frequencies in PCI and CABG group (3.2 vs. 2.8). They attributed the lower MI rates in their research to adopting the strictest definition of MI available .
However, other studies revealed different results; the updated NOBLE study reported the frequency of post-procedural myocardial infarction among the PCI and CABG was 8% and 3%, respectively .
In long-term follow-up, the revascularization rate was greater among the CABG as compared to PCI in the current study but this increase was statistically insignificant (2.1 in CABG group % vs. 0% in PCI group). This could be attributed to proper selection of patient candidate to PCI and the highly efficient drug-eluting stents used nowadays. Moreover, a possible explanation of our results relay on the fact that the PCI patients had lower frequencies of LMCAD, lower SYNTAX score and lesser number of presenting lesions than the CABG group.
This finding is contradicting that published. Gimbel et al. reported target revascularization rate of and 5.8% and 12.5% in and CABG and PCI group, respectively, owing to commonly occurring unsuccessful revascularization (restenosis) following PCI than following CABG (graft failure) or by more complete revascularization following CABG than following PCI. Nevertheless, it is speculated that full revascularization is not necessary in these older patients to provide a decent long-term prognosis .
In the long-term follow-up of PCI patients compared to CABG, a higher risk of recurrent revascularization may be due to complicated anatomy and contrast agent limitations in PCI.
Moreover, the EXCEL trial reported similar findings in long-term follow-up of PCI and CABG regarding repeated revascularization being 11.6% and 5.8% in PCI and CABG groups, respectively. It is worth mentioning that most of revascularization was repeated by PCI procedures. Nevertheless, repeated revascularization is more likely correlated with MI and death .
As expected, the cerebrovascular stroke frequency was greater among the CABG than the PCI group being 4.3% in the former and 2% in the latter, yet this distinction was statistically insignificant.
This result is concurrent with multiple clinical studies such as CARDIA, PRECOMBAT extended, EXCEL follow-up, FREEDOM, and BEST trials, where the frequencies of cerebrovascular stroke in PCI group were 0.4, 1.9, 0.5, 2.4, and 2.5, respectively, while those of the CABG group were 2.8, 2.2, 0.8, 5.2, and 2.9, respectively [9, 12, 21,22,23].
These frequencies are slightly less in the PCI group as compared to the CABG group, yet some did not achieve the statistically significant level too.
The ascending atherosclerosis in the aorta could be related with the long-term incidence of cerebrovascular stroke post-CABG. Moreover, increased risk of factors in the aging process might be a possible explanation of cerebrovascular disease in CABG patients. Among the major risk factors, stroke are advanced age, previous stroke, previous stenosis of carotid artery, and previous PVD increased operation time and postoperative atrial fibrillation [24, 25]. The delayed factors associated with increased occurrence of stroke in CABG patients include decreased cardiac output, atrial fibrillation, myocardial infarction, and thrombophilia. Carotid stenosis, hypertension, peripheral vascular disease, diabetes mellitus, recent myocardial infarction, and/or renal failure are among the conditions that put patients at an elevated stroke risk following cardiac surgery.
Another possible etiological factor is association with unstable angina which could be attributed to the ongoing chronic inflammatory process in such patients as supported by the active inflammatory process in conjunction with building up of macrophages at the sites of ruptured plaques and consequently leading to increased thrombosis .
Furthermore, other studies showed a contradicting result. They stated that the cerebrovascular stroke was higher in the PCI group compared with the CABG group. Martins et al., NOBLE, and updated NOBLE are among these studies. The rate of occurrence of stroke in the PCI among these groups were 3.2%, 5%, and 4%, respectively, compared to 1.8%, 2%, and 4% in the CABG group, respectively [20, 27].
They explained such findings owing to lowering of repeat revascularization rate in the CABG group, as the repetition technique is linked to poor prognosis. They added that this might be partly justified by stent restenosis, incomplete revascularization in more complex cases. Another possible cause is that after 1 year, there is occurrence of cerebrovascular stroke in the PCI group, overlapping the stoppage of dual antiplatelet therapy inhibition. Yet, the decreased incidence of cerebrovascular stroke could be due chance [8, 27].
Finally, we reported that none of our cases in the long-term follow-up care experienced bleeding neither in the CABG nor the PCI groups. This could be explained by the advancement in performances in both procedures and skillful heart teams and proper management protocols applied in both techniques.
By exploring available literature, we noted an increased bleeding rate among CABG group than the PCI group (3.1% in CABG group versus 0.7% in PCI group) in the research study performed by Gimbel et al. .
The best trial too revealed that the fatal bleeding rate among the CABG and PCI group was 1.6% and 0.7%, respectively, while bleeding frequency with reference to thrombolysis in myocardial infarction (TIMI) was 6.8 in the PCI and 29.9 in the CABG group. CABG group’s remarkably higher rate is mostly attributed to an effect of the operation .
In conclusion, in the current retrospective study, no statistically considerable distinction between PCI and CABG was found concerning long-term follow-up incidence rates of MACE, heart failure, stroke composite of death, or MI, or among elderly patients having MVD. As a result, in long-term follow-up, the use of drug-eluting stents (DES) was not equivalent to CABG in terms of significant adverse cardiac events.
Furthermore, PCI can provide a substitute and safe approach to CABG in properly selected patients. However, CABG seems to provide more complete revascularization as denoted by the residual SYNTAX.
The ultimate medical judgment should be designated on a person’s baseline characteristics incorporating all the circumstances, taking in consideration life expectancy and quality of life.
The present study had inadequate statistical strength to permit a solid deduction, and further investigation is indispensable in this field.