Two hundred forty-seven patients aged 45 years or younger were entered into the registry between June 04, 2016, and June 10, 2019. The demographic and clinical characteristics of the patients are presented in Table 1. The mean age of this patient cohort was 39.36±5.21, with a range of 19 to 45 years. Sixteen out of 2341 registered patients (0.68%) experienced STEMI at age 30 or younger. The majority of patients were male (91.8%), with no statistically significant difference between males and females in terms of age (p=0.250).
CVD risk factors
The most common CVD risk factors were smoking (56.7%), followed by low high-density lipoprotein (HDL) (55.5%), elevated triglyceride (44.4%), hypertension (38.2%), hypercholesterolemia (38.1%), elevated low-density lipoprotein (LDL) (26.3%), and obesity (24.3%). Only 8 (3.2%) patients did not have any of the main CVD risk factors, yet, the study did not query the early family history of CVD or physical activity.
Hospital arrival
Patients’ first contacts with medical professional were as follows: most patients (79.8%) were directly transported to the ED by a private vehicle, 30(12.1%) visited a general practitioner first, and 20(8.1%) called the emergency services. Only 26 (10.5%) arrived at the hospital by ambulance, and 76(30.8%) patients were first admitted to a non-PCI center and later transferred to a PCI center (Table 1).
Table 1 Demographics, CVD risk factors and hospital arrival of young adults with STEMI (n=247)
n(%)
|
Variable
|
N(%)
|
Variable
|
|
BMI
|
|
Age group
|
63(25.5)
|
<25
|
16(6.5)
|
<=30
|
184(74.5)
|
≥25
|
231(93.5)
|
31-45
|
140(56.7)
|
Current smoker
|
227(91.8)
|
Males
|
5(2.0)
|
Previous stroke /TIA
|
|
Previous MI
|
0(0)
|
History of hypothermia
|
20(8.1)
|
Yes
|
29(11.7)
|
Previous angina
|
223(90.3)
|
No
|
4(1.6)
|
History of heart failure
|
4(2.6)
|
Unknown
|
6(2.4)
|
Previous CABG
|
|
Hypercholesterolemia
|
9(3.6)
|
Previous PCI
|
47(19)
|
Yes
|
1(0.4)
|
History of Renal Failure
|
193(81)
|
No
|
1(0.4)
|
Current malignancy
|
0(0)
|
Unknown
|
|
History of sleep apnea
|
36(14.6)
|
History of hypertension
|
5(2.0)
|
Yes
|
9(3.6)
|
Treated hypertension
|
38(15.4)
|
No
|
|
History of atrial fibrillation
|
204(82.6)
|
Unknown
|
0(0)
|
Yes
|
55(22.3)
|
Other life limiting disease
|
235 (96.1)
|
No
|
|
Type of first medical contact
|
12(4.9)
|
Unknown
|
20(8.1)
|
Paramedics
|
|
Familial hypercholesterolemia
|
197(79.8)
|
Emergency Room staff
|
6(2.2)
|
Yes
|
30(12.1)
|
General practitioner
|
138(55.8)
|
No
|
|
Type of patient transport to hospital
|
104(42)
|
Unknown
|
26(10.5)
|
Ambulance
|
|
Diabetes mellitus
|
221(89.5)
|
Private vehicle
|
27(10.9)
|
Yes
|
|
First Admission site
|
215(98.1)
|
No
|
171(69.2)
|
A PCI center
|
5(2)
|
Unknown
|
76(30.8)
|
A non-PCI center
|
|
|
MI: myocardial infarction; BMI: Body mass index; TIA: transient ischemic attack;
CABG: coronary artery bypass graft; PCI: Percutaneous Coronary Intervention
Clinical presentations
Patients’ clinical characteristics are summarized in Table 2. All patients presented with chest pain (100%), 46(18.6%) had a heart rate that was not within the normal range of 60-100 beats per minutes (bpm), 192(78%) had a systolic blood pressure either below or above the normal range of 90-119 mmHg, and 38.2% were hypertensive (SBP≥14). The mean earliest ejection fraction was 41.67±7.65, which dropped to 39.80±8.66 at later stages; 27.5% of patients experienced a decline in ejection fraction (<40%) in the early stage. The Killip classification in the majority of patients (96%) was I, indicating no sign of heart failure. Most patients (96.8%) had at least one coronary artery with more than 50% stenosis, and 22% had three coronary arteries with above 50% stenosis. The culprit artery was identifiable in 97.8% of patients who underwent angiography; the most common culprit artery was the left anterior descending artery (58.1%), followed by the right coronary artery (25.1%). Over 53% of MIs were anterior, including anterior, anteroseptal, extensive anterior, and anterolateral, while the remaining (46.6%) were inferior, lateral, lateral inferior, or posterior. Atrial fibrillation was present in the first ECG of 3 (1.2%) patients.
Table 2. Clinical characteristics of the study sample
Variables
|
Mean(SD)
|
n(%)
|
Heart rate in the first ECG, bpm
60-100
<60
>100
|
81.00 (19.64)
|
201(81.4)
18 (7.3)
28(11.3)
|
SBP at presentation, mmHg
<90
90-119
120-139
≥140
|
129.26 (23.48)
|
14(5.7)
54(22)
84(34.1)
94(38.2)
|
The earliest EF, %
<40
41-49
≥50
|
41.67(7.65)
|
68(27.5)
95(38.5)
84(34.0)
|
The latest EF (measured before discharge), %
|
39.80(8.66)
|
|
The Killip classification
I
II
III or IV
|
|
237(96)
1(0.4)
9(3.6)
|
Number of coronary arteries with stenosis >50% (n=186)
0
1
2
3
|
|
6(3.2)
85(45.7)
54(29.0)
41(22.0)
|
The culprit artery (n=186)
LAD
RCA
CX
OM
PLV
PDA
Others
|
|
104(58.1)
45(25.1)
18(7.3)
10 (15.6)
1(0.4)
1(0.4)
2(0.8)
|
AF in the first ECG
|
|
3(1.2)
|
ECG: electrocardiogram; SBP: systolic blood pressure; EF: ejection fraction; PLV: the posterolateral artery; LAD: the left anterior descending artery; RCA: the right coronary artery; CX: the circumflex artery; OM: the obtuse marginal; PDA: the posterior descending artery; AF: atrial fibrillation.
Laboratory findings
The results of laboratory tests revealed that 46 out of 226 patients (20.3%) had abnormal hemoglobin level, 10 out of 246 patients (4.1%) abnormal platelet, 137 out of 241 patients (56.8%) increased white blood cells, 61 out of 232 patients (26.3%) elevated LDL, 102 out of 229 patients (55.5%) HDL level lower than 40mg/dl, 99 out of 223 patients (44.4%) had triglyceride above 150mg/dl, 90 out of 236 (38.1%) showed total cholesterol level above 200mg/dl, and 67 out of 238 patients (28.1%) had blood glucose level above 140mg/dl at the ED presentation. In addition, in 178 out of 208 patients (72.06%), creatine phosphokinase (CPK) was elevated, 53 out of 233 patients (22.7%) had increased CK-MB level, but only 8 out of 233 patients (3.4%) had elevated troponin at the ED presentation (Table 3).
Table 3. The laboratory test results of the study sample
Variables
|
Mean (SD)
|
n(%)
|
The earliest Hb (pre intervention), g/dL
Low (<13.5 ♂, <12.0 ♀)
Normal (13.5-17.5 ♂, 12.0-15.5 ♀)
High (>17.5 ♂,> 15.5 ♀)
|
15.41(1.76)
|
38 (16.8)
180(79.6)
8(3.5)
|
The earliest platelet count, 109 cells/l
<150.000
150.000-450.000
>450.000
|
261.65(69.18)
|
8(3.3)
236(95.9)
2(0.8)
|
The earliest WBC, 109 cells/l
<4500
4500-11000
>11000
|
11.99(3.51)
|
0(0)
104(43.2)
137(56.8)
|
LDL, mg/dl
<129
130-159
>160
|
111.74(33.93)
|
171(73.7)
45(19.4)
16(6.9)
|
HDL, mg/dl
<40
≥40
|
40.56(9.86)
|
127(55.5)
102(44.5)
|
Triglyceride, mg/dl
<150
150-199
≥200
|
172.64(116.22)
|
124(55.6)
40(17.9)
59(26.5)
|
Total cholesterol, mg/dl
<200
200-239
>240
|
187.76(45.38)
|
146(61.9)
64(27.1)
26(11.0)
|
The earliest creatinine, mg/dl
|
1.13(0.71)
|
|
The highest creatinine, mg/dl
|
1.17(0.75)
|
|
BGL at presentation, mg/dl
<140
140-199
>200
|
144.76(101.19)
|
171(71.8)
36(15.1)
31(13.0)
|
CPK at presentation, u/l
Normal (39-308 for men, 26-192 for women)
Increased
|
1788(1633.26)
|
30(12.14)
178(72.06)
|
The highest CPK, u/l
|
2186(1839.17)
|
|
The earliest CK-MB, ng/ml
5-25
>25
|
35.21(52.92)
|
180(77.3)
53(22.7)
|
The highest CK-MB, ng/ml
|
141(118.79)
|
|
The earliest troponin, ng/ml
≤ 0.4
> 0.4
|
0.24(1.84)
|
225(96.6)
8(3.4)
|
The highest troponin, ng/ml
|
10.47(16.55)
|
|
LDH at presentation, u/l
|
529(463.45)
|
|
ESR at presentation, mm/h
Normal (0-15 ♂, 0-20 ♀)
Increased
|
9.23(9.23)
|
150(85.22)
26(14.77)
|
♂men; ♀ women; Hb: hemoglobin; WBC: white blood cells; BGL: blood Glucose level; CPK: creatine phosphokinase; CK-MB: creatine kinase-MB
Primary percutaneous coronary intervention
Of 227 patients, 177(71.7%) were eligible to receive primary percutaneous coronary intervention and 54(21.9%) thrombolytic therapy (Table 4). Sixteen (6.5%) patients were not eligible for reperfusion therapy due to reasons such as late presentation, spontaneous reperfusion, and patient refusal. Primary PCI was conducted on 155(62.8%) patients, and 22 (12.42%) patients did not receive intended primary PCI for reasons such as technical issues, lack of facilities, no longer being eligible, patient refusal, and undergoing coronary artery bypass graft (CABG). Of patients who underwent primary PCI, 63 patients (35.4%) received thrombectomy and 161 (90.4%) stent placement, including Bare-metal stents (1.9%) and drug-eluting stents (98.1%). A stenosis> 50% was presented in only three patients (1.6%) after performing primary PCI.
Table 4. The frequency of intended and performed interventions
Interventions
|
n/%
|
Intended reperfusion (n=227)
|
|
No intended primary PCI
|
16(6.5)
|
Primary PCI
|
177(71.7)
54(21.9)
|
Thrombolytic therapy
|
Reasons for no intended primary PCI
|
Late presentation
|
7(43.8)
1(6.3)
2(12.5)
6(6.3)
|
Spontaneous reperfusion
|
Patient refusal
|
Not mentioned/missing
|
Performed interventions (n=227)
|
Primary PCI
|
155(62.8)
55(22.3)
37(15.0)
|
Thrombolytic therapy
|
Medical therapy only
|
Reasons for not performing intended primary PCI (n=22)
|
Not applicable
|
6(27.2)
5(22.7)
3(13.6)
8(36.3)
|
Thechnical problems/lack of facilties/patients refusal
|
Diagnosis not STEMI
|
Needed emergency CABG
|
Type of artery access for PCI (n=173)
|
Radial
|
86(46.2)
100(53.8)
|
Femoral
|
PCA: percutaneous coronary artery
Early complications after STEMI
None of the patients developed recurrent MI, stent thrombosis, or mechanical complications during the hospitalization period. However, one patient (0.4%) developed transient ischemic attack (TIA), 9(3.6%) patients required blood transfusion, 19 (7.7%) patients had severe bleeding, 30(12.1%) patients developed heart failure, and 14 (5.7) patients had the Killip class IV, and 6(2.4%) patients experienced atrial vibration. In addition, 2(0.8) patients experienced cardiac arrest, underwent mechanical ventilation, and died before discharge.