Evaluation of algorithms for registry-based detection of acute myocardial infarction following percutaneous coronary intervention

Figures & data

Table 1 Algorithms for detection of acute myocardial infarction following percutaneous coronary intervention in the Danish National Patient Registry

Algorithm	AMI diagnosis	Admission type	Hospital
A	Primary or secondary	All inpatients	All hospitals
B	Primary only	All inpatients	All hospitals
C	Primary or secondary	Acute admissions only	All hospitals
D	Primary only	Acute admissions only	All hospitals
E	Primary or secondary	Acute admissions only	Hospitals with CAG capability
F	Primary only	Acute admissions only	Hospitals with CAG capability

Abbreviations: AMI, acute myocardial infarction; CAG, coronary angiography.

Table 2 Baseline characteristics of patients with percutaneous coronary intervention

	N=5,719
Demographics and comorbidities
Age, years, median (IQR)	66 (58–73)
Male sex	4,271 (74.7)
Body mass index >30 kg/m^2	1,308 (22.9)
Active smokinga	1,819 (31.8)
Treatment for hypertensiona	3,046 (53.3)
Treatment for hypercholesterolemiaa	3,625 (63.4)
Diabetesa	905 (15.8)
Charlson comorbidity index =0	2,679 (46.8)
Charlson comorbidity index =1	1,448 (25.3)
Charlson comorbidity index ≥2	1,592 (27.8)
Procedure characteristics
More than one stent	2,212 (38.7)
Stent length ≥20 mm	3,025 (52.9)
PCI indication ACS	2,650 (46.3)
PCI indication SAP	2,878 (50.3)
Calendar year of percutaneous coronary intervention
2006	718 (12.6)
2007	643 (11.2)
2008	643 (11.2)
2009	1,050 (18.4)
2010	1,005 (17.6)
2011	942 (16.5)
2012	718 (12.6)

Notes: Data presented as number (%) unless otherwise stated.

a Missing information was <3%, missing values on smoking, diabetes and treatment were considered “not smoking”, “not having diabetes”, and “not treated”, respectively.

Abbreviations: IQR, interquartile range; PCI, percutaneous coronary intervention; ACS, acute coronary syndrome; SAP, stable angina pectoris.

Figure 1 Sensitivity vs 1-positive predictive value for algorithms A–F.

Notes: A, diagnosis type: primary or secondary, all inpatients; B, diagnosis type: primary, all inpatients; C, diagnosis type: primary or secondary and acute admission; D, diagnosis type: primary and acute admission; E, diagnosis type: primary or secondary and acute admission at a hospital with coronary angiography capability; and F, diagnosis type: primary and acute admission at a hospital with coronary angiography capability.
Abbreviation: PPV, positive predictive value.

Table 3 Performance of algorithms for detection of acute myocardial infarction following percutaneous coronary intervention in the Danish National Patient Registry

Algorithm	Sensitivity, % (95% CI)	Specificity, % (95% CI)	Negative predictive value, % (95% CI)	Positive predictive value, % (95% CI)
A	95.2 (92.2–97.3)	93.4 (92.7–94.0)	99.7 (99.6–99.9)	41.7 (37.9–45.7)
B	85.0 (80.5–88.8)	98.2 (97.8–98.5)	99.2 (99.0–99.4)	70.4 (65.4–75.1)
C	93.9 (90.6–96.3)	98.3 (97.9–98.6)	99.7 (99.5–99.8)	73.4 (68.6–77.8)
D	82.1 (77.3–86.3)	99.0 (98.7–99.2)	99.1 (98.8–99.3)	81.0 (76.1–85.2)
E	67.7 (62.1–73.0)	99.0 (98.7–99.2)	98.3 (98.0–98.7)	78.0 (72.5–82.8)
F	58.0 (52.1–63.6)	99.5 (99.3–99.7)	97.8 (97.4–98.2)	86.8 (81.4–91.0)

Note: A, diagnosis type: primary or secondary, all inpatients; B, diagnosis type: primary, all inpatients; C, diagnosis type: primary or secondary and acute admission; D, diagnosis type: primary and acute admission; E, diagnosis type: primary or secondary and acute admission at a hospital with coronary angiography capability; and F, diagnosis type: primary and acute admission at a hospital with coronary angiography capability.

Abbreviation: CI, confidence interval.

Table 4 Performance of algorithm C (all acute admissions with acute myocardial infarction as primary or secondary discharge diagnosis) across subgroups

	Sensitivity, % (95% CI)	Specificity, % (95% CI)	Negative predictive value, % (95% CI)	Positive predictive value, % (95% CI)
Sex
Female	91.7 (83.6–96.4)	98.0 (97.2–98.7)	99.6 (99.1–99.8)	71.0 (61.2–79.4)
Male	94.7 (91.0–97.1)	98.3 (97.9–98.7)	99.7 (99.5–99.9)	74.2 (68.7–79.2)
Age
≤65 years	95.7 (90.8–98.3)	98.3 (97.7–98.7)	99.8 (99.6–99.9)	70.7 (63.3–77.4)
>65 years	92.6 (87.9–95.9)	98.2 (97.7–98.7)	99.6 (99.3–99.8)	75.5 (69.2–81.1)
Indication for stent implantation
Acute coronary syndrome	93.0 (87.9–96.3)	97.5 (96.9–98.1)	99.6 (99.3–99.8)	68.0 (61.2–74.3)
Stable angina pectoris	94.9 (90.2–97.7)	98.9 (98.4–99.2)	99.8 (99.5–99.9)	79.8 (73.1–85.4)
Prior myocardial infarction
Myocardial infarction prior to index admission	96.1 (90.9–98.7)	97.8 (96.8–98.5)	99.7 (99.2–99.9)	78.4 (70.6–84.9)
Myocardial infarction at index admission	92.4 (85.0–96.8)	97.3 (96.4–98.0)	99.6 (99.2–99.8)	62.9 (53.9–71.3)
No prior myocardial infarction	92.9 (86.5–96.7)	99.1 (98.6–99.4)	99.7 (99.5–99.9)	78.4 (70.3–85.2)
Time from stent implantation to detection of acute myocardial infarction
0–30 days	89.7 (74.9–97.0)	99.5 (99.3–99.7)	99.9 (99.9–100)	50.0 (36.7–63.3)
>30–1 year	94.2 (87.7–97.7)	99.3 (99.1–99.5)	99.9 (99.8–100)	67.5 (58.8–75.4)
<1 years	94.8 (89.6–97.8)	98.8 (98.5–99.1)	99.9 (99.8–100)	63.0 (55.6–69.9)
1–<2 years	98.1 (91.7–99.8)	99.5 (99.2–99.7)	99.9 (99.8–100)	72.6 (61.6–81.8)
2–<3 years	89.8 (80.2–95.6)	99.8 (99.6–99.9)	99.8 (99.7–99.9)	88.3 (78.5–94.6)
3–<4 years	94.1 (82.4–98.8)	99.8 (99.6–99.9)	99.9 (99.7–100)	88.9 (75.7–96.1)
4–<5 years	88.2 (67.3–97.5)	100 (99.8–100)	99.9 (99.7–100)	100 (78.2–100)
>30 days to 5 years	93.6 (90.1–96.1)	98.7 (98.4–99.0)	99.7 (99.5–99.8)	77.2 (72.3–81.7)

Abbreviation: CI, confidence interval

Table S1 Two-way table for detection algorithm A

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	258	13	271
No AMI	360	5,088	5,448
Total	618	5,101	5,719

Note: I21 as either primary or secondary discharge diagnoses for an inpatient, all admission types (acute or elective), and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.

Table S2 Two-way table for detection algorithm B

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	238	42	280
No AMI	100	5,339	5,439
Total	338	5,381	5,719

Note: I21 as primary discharge diagnoses for an inpatient, all admission types (acute or elective), and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.

Table S3 Two-way table for detection algorithm C

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	262	17	279
No AMI	95	5,345	5,440
Total	357	5,369	5,719

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.

Table S4 Two-way table for detection algorithm D

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	230	50	280
No AMI	54	5,385	5,439
Total	284	5,435	5,719

Note: I21 as primary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.

Table S5 Two-way table for detection algorithm E

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	191	54	245
No AMI	91	5,384	5,475
Total	282	5,438	5,719

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital with coronary angiography capability.

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.

Table S6 Two-way table for detection algorithm F

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	164	119	283
No AMI	25	5,411	5,436
Total	189	5,530	5,719

Note: I21 as primary discharge diagnoses, acute admission, and hospital with coronary angiography capability.

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S7 Two-way table for algorithm C stratified for female sex

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	66	6	72
No AMI	27	1,349	1,376
Total	357	1,355	1,448

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S8 Two-way table for algorithm C stratified for male sex

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	196	11	207
No AMI	68	3,996	4,064
Total	264	4,007	4,271

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S9 Two-way table for algorithm C stratified for age ≤ 65 years

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	111	5	116
No AMI	46	2,647	2,693
Total	157	2,652	2,809

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S10 Two-way table for algorithm C stratified for age > 65 years

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	151	12	163
No AMI	49	2,698	2,747
Total	200	2,710	2,910

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S11 Two-way table for algorithm C stratified for indication of index stent, acute coronary syndrome

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	132	10	142
No AMI	62	2,446	2,508
Total	194	2,456	2,650

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S12 Two-way table for algorithm C stratified for indication of index stent, stable angina

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	130	7	137
No AMI	33	2,899	2,932
Total	163	2,906	3,069

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S13 Two-way table for algorithm C stratified on acute myocardial infarction prior to index admission

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	98	4	102
No AMI	27	1,189	1,216
Total	125	1,193	1,318

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S14 Two-way table for algorithm C stratified on acute myocardial infarction at index admission

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	73	6	79
No AMI	43	1,541	1,584
Total	116	1,547	1,663

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S15 Two-way table for algorithm C stratified on no prior acute myocardial infarction

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	91	7	98
No AMI	25	2,616	2,641
Total	116	2,623	2,739

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S16 Two-way table for algorithm C stratified on time from admission, 0–30 days

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	26	3	29
No AMI	26	5,664	5,690
Total	52	5,667	5,719

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S17 Two-way table for algorithm C stratified on time from admission, >30 days to 1 year

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	81	5	86
No AMI	39	5,527	5,566
Total	120	5,532	5,652

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S18 Two-way table for algorithm C stratified on time from admission, < 1 year

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	109	6	115
No AMI	64	1,628	1,692
Total	173	1,634	1,807

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S19 Two-way table for algorithm C stratified on time from admission, 1–2 years

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	53	1	54
No AMI	20	90	110
Total	73	91	164

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Registry; AMI, acute myocardial infarction.

Table S20 Two-way table for algorithm C stratified on time from admission, 2–3 years

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	53	6	59
No AMI	7	1,489	1,496
Total	60	1,495	1,555

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.

Table S21 Two-way table for algorithm C stratified on time from admission, 3–4 years

	Detected in DNPR
Detected in end point committee	AMI	No AMI	Total
AMI	32	2	34
No AMI	4	61	65
Total	36	63	99

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.

Table S22 Two-way table for algorithm C stratified on time from admission, 4–5 years

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	15	2	17
No AMI	0	2,077	2,077
Total	15	2,079	2,094

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.

Table S23 Two-way table for algorithm C stratified on time from admission, >30 days to 5 years

	Detected in DNPR
Detected in end-point committee	AMI	No AMI	Total
AMI	234	16	250
No AMI	69	5,333	5,402
Total	303	5,349	5,652

Note: I21 as either primary or secondary discharge diagnoses, acute admission, and hospital (with or without coronary angiography capability).

Abbreviations: DNPR, Danish National Patient Register; AMI, acute myocardial infarction.