The main finding of our study is that in NSTEACS patients with multivessel disease, coronary revascularization strategies (total, staged, or FFR guided) are comparable regarding immediate and short-term (6 months) clinical follow-up.
We included ninety patients in our study who presented to the ER with NSTEACS in our hospital, in an 8-month period. Being performed in a military medical hospital may explain the predominance of the male gender among the study population. The similarity of basic characteristics and laboratory findings of patients in the three groups (regarding demographic criteria, risk factors, clinical presentation, ECG, echocardiography, laboratory, and angiographic findings) allows for a better comparison among the three groups.
Indeed, our study protocol was similar to the FAMOUS-NSTEMI trial, which found that FFR disclosure resulted in a change in the treatment plan of 144 patients planned for PCI. After applying FFR, only 117 patients underwent PCI [8]. This could be explained by the fact that measuring FFR changes the classification of stenosis from “significant stenosis” for PCI to “non-significant stenosis” managed by only optimal medical treatment. In agreement with the results of the FAME trial, we found that significantly less stents per patient were placed in the FFR group than in the other groups [9]. Furthermore, the 2-year follow-up of the FAME Study found that the number of stents used was 2.7 ± 1.2 in the angiography-guided group and 1.9 ± 1.3 in the FFR-guided group (p < 0.001) [10]. This is explained simply due to less number of lesions indicated for PCI after measuring FFR.
Our study found that the volume of contrast used was least in the staged group than that used in the total and FFR groups. In agreement with our results, the “CvLPRIT” trial demonstrated that total contrast used was 250 (190–330) ml in the “complete revascularization group” versus 190 (150–250) ml in the “infarct-related artery (IRA)-only revascularization group” (P value < 0.0001) [6].
Regarding the mean procedure, we found that duration was least in the staged group than in the total and FFR groups. Similarly, in the CvLPRIT trial, the total procedure time was 55 (38–74) min in the “complete” revascularization group, while in the “infarct-related artery (IRA)-only revascularization group,” it was 41 (30–55.5) min (P value < 0.0001) [6]. This can be explained by the fact that in the staged group, the duration of the procedure and volume of contrast needed to deploy stent(s) in only one vessel are significantly lower than that needed to fix all stenosed vessels in the total group or all the functionally significant lesions in the FFR group.
Regarding the procedure outcome, our study found that there was no statistically significant difference between the three groups. In concordance with our results, the FAMOUS-NSTEMI trial found that in-hospital adverse events were similar in the “FFR-disclosure group” and “angiography group” [8]. Also, the “CvLPRIT trial” found that the periprocedural events and ischemia testing were similar in the complete revascularization and IRA-only revascularization groups [6]. In contrast to our results, the “FAME Study” found that hospital stay at baseline admission was significantly more in the angiography group than that in the FFR group [10].
We found that major acute cerebrovascular and cardiac events were comparable among the three groups at the 6-month follow-up. In agreement with our results, the FAMOUS-NSTEMI trial found that 14 (8.0%) of 176 patients in the “FFR-guided group” and 15 (8.6%) of 174 in the “angiography-guided group” experienced cardiac death, non-fatal myocardial infarction, or heart failure hospitalization (P = 0.89). Myocardial infarction relating to revascularization occurred in 5 (2.8%) patients in the “FFR-guided group” and 11 (6.3%) patients in the “angiography-guided group” (P = 0.12). Major adverse cardiac events excluding MI related to revascularization occurred in 10 (5.7%) patients in the “FFR-guided group” and 5 (2.9%) patients in the “angiography-guided group” (P = 0.25) [8]. Also supporting our results, the FAME Study showed that all-cause mortality at 2 years was 3.8% (n = 19) in the angiography-guided group and 2.6% (n = 13) in the FFR-guided group (p = 0.25). After 2 years, MACE had occurred in 111 patients (22.4%) in the angiography-guided group and in 91 patients (17.9%) in the FFR group (p = 0.08) [10]. According to the results of our study, there was no statistically significant difference between the three groups in the hospital outcome or in the short-term outcome.
In contrast to our results, the major findings of “SMILE trial” were as follows: “one-stage” complete coronary revascularization is superior to “multistage” complete coronary revascularization in terms of MACE [7]. Similarly, the “CvLPRIT trial” found that MACE was significantly lower in the complete revascularization arm (10.0%) than in the IRA-only arm (21.2%) [6]. Another study observed that complete coronary revascularization is associated with a lower rate of the composite endpoint (death, myocardial infarction, or revascularization) [11].
Interestingly, we found that the FFR-guided approach resulted in changes in stenosis classification and patient management in 23.33% (n = 7) of the FFR group patients. The rate of coronary revascularization was reduced at the index procedure, and this difference was maintained at 6 months.
Finally, we believe that a larger and longer study may be necessary to properly assess the differences between the three management plans regarding health outcomes and cost-effectiveness.
Limitations
A small sample size that is limited only to a single center was the most prominent limitation. A short-term follow-up period was implemented; however, a longer period is needed to detect all possible health care outcomes. A cost-benefit study of each management plan was not performed, which may help to set management policies in developing countries with limited resources.