Which One Should be Treated in the Setting of Acute ST Elevation Myocardial Infarction - Culprit Lesion or Culprit Vessel?
The current guidelines still recommend emergent PCI of the culprit lesion and state that
primary PCI should be limited to the culprit vessel with the exception of cardiogenic shock
and persistent ischaemia after PCI of the supposed culprit lesion. This recommendation is
based on a high number of studies. However, several studies are present about the safety and
efficacy of non-culprit vessel PCI during acute MI. Nowadays, the debate is increasingly
going on about the PCI of the non-culprit arteries during the index event with newer
prospective randomized studies. Besides, it is still unclear for the culprit artery whether
to treat only the culprit lesion or all the other lesions in the culprit vessel during the
index event. The present report describes a retrospective comparison between the two
strategies during primary PCI for STEMI, looking for their influence on the clinical and
angiographic course of the patients.
Patient selection: This multi-centre retrospective study included patients from 3
high-volume primary PCI centres in Turkey. A total number of 5512 patients underwent
emergent PCI for acute STEMI between January 2011 and December 2013. From this patient
population, patients were looked for the presence of an additional lesion to the culprit
lesion (CL). Additional lesion was defined as the presence of an angiographically severe
(≥70%) lesion other than the CL either proximal or distal to it in the same coronary artery
after the distal flow was observed most commonly as a result of guide-wire passage or PTCA
of the total occlusion.
Exclusion criteria: - Presence of LMCA lesion
- Cardiogenic shock
- Previous CABG operation
- Decision for CABG operation after primary PCI
- Severe valvular disease including aortic stenosis of mitral insufficiency
- Severe kidney disease (serum creatinine >2.5 mg/dl or patients on maintenance
- Rejection of second PCI by the patient after the index event
The eligible patients were retrospectively sought from the database of the relevant
hospital. The basal characteristics of the patients like age, sex, presence of coronary risk
factors (smoking, hypertension, diabetes mellitus and hyperlipidemia), vital signs and
location of STEMI at admission were noted. The emergent coronary angiograms of the patients
were then examined and several angiographic and post-PCI features which are defined in
detail in the following sections were addressed. Follow-up of these patients were succeeded
either by phone call, routine polyclinic visits or from the database of hospital.
Study groups: Patients were grouped into 2 according to the PCI strategy; culprit vessel
(CV) group including patients who underwent emergent PCI of all severe (≥70 stenosis in CAG)
lesions in the culprit vessel and culprit lesion (CL) group including patients who underwent
emergency PCI only for the CL and staged PCI in 2 weeks for the other additional lesions in
the CV. Both groups underwent staged PCI for the severe lesion(s) in non-culprit vessel(s)
if necessary in a different session in 28 days after the index event. Staged PCI was the
preferred strategy in both groups if necessary because staged PCI has been found to be at
least non-inferior to other strategies in several studies [3, 4, 10, 13].
Definition of acute STEMI: The criteria for diagnosis of STEMI were: (1) chest pain within
24 h before admission that lasted for more than 30 min and was not relieved by sublingual
nitroglycerin; (2) ST-segment elevation on electrocardiogram; and (3) elevated serum
creatine kinase (CK) or troponin levels.
Emergent coronary angiography and PCI procedure: All patients were routinely treated with
heparin, clopidogrel, aspirin, statin and an angiotensin converting enzyme inhibitor or
angiotensin II receptor blocker unless contraindicated.
Coronary angioplasty and stent implantation were performed according to standard
percutaneous techniques through the femoral artery. Standard selective coronary angiography
with at least 4 views of the left coronary system and 2 views of the right coronary artery
was performed using the Judgkins technique.
All the patients with the diagnosis of acute STEMI underwent emergent PCI with bare metal or
drug-eluting stents. Stent implantation was performed at an inflation pressure of 10 to 16
atm. When suboptimal stent deployment was observed, angiographic optimization was performed
using high-pressure noncompliant balloon dilatation to achieve <20% residual stenosis by
visual estimation. Angiographic no-reflow phenomenon was diagnosed if a significant coronary
flow decrease (Thrombolysis In Myocardial Infarction [TIMI] grade <3 flow) without
mechanical obstruction was noticed in final cineangiograms obtained at completion of the PCI
procedure [14, 15].
Staged PCI: Staged PCI procedure was performed either to the culprit vessel in CL group
and/or to the non-culprit lesion(s) in non-culprit vessel(s) in both groups in 14 days after
the index event. In the CL group, it was performed to culprit and non-culprit vessels during
same intervention. In the CV group, it was performed to non-culprit vessels if necessary.
Follow-up of patients: The investigators collected follow-up information from the database
of the hospitals and/or during telephone calls with patients. Follow-up included screening
for major outcomes including death (in-hospital, cardiac and non-cardiac), non-fatal
myocardial infarction, and need for surgical or percutaneous revas¬cularisation.
Myocardial infarction was defined as a troponin level above the 99th percentile and symptoms
of cardiac ischemia. For patients with re-infarction, the definition required ≥20% increase
of cardiac markers (Troponin) with ischemic symptoms or ECG findings or angiographic
evidence of coronary artery occlusion including early stent thrombosis. Early stent
thrombosis was defined as acute myocardial infarction due to stent thrombosis in 30 days
after implantation, usually during index hospitalization.
Statistical analysis: The analysis of the results was performed using the Predictive
Analytics SoftWare (PASW) Statistics 18.0 for Windows (Statistical Package for the Social
Sciences, SPSS Inc., Chicago, Illinois). Data were tested for a normal distribution using
the Kolmogorov-Smirnov test. The categorical variables were shown as numbers of cases with
percentages and the normally distributed continuous variables were shown as mean ± SD.
Student's t-test was used for the analysis of the continuous variables that were normally
distributed and the χ2 test for the categorical variables. The Kruskal-Wallis rank-sum test
was used for the variables that were not normally distributed. Statistical significance was
defined as p value less than 0.05.
myocardial infarction, TIMI flow, culprit lesion, culprit vessel
Samsun Education and Research Hospital
Samsun Education and Research Hospital