Acute Cardiovascular Events After COVID-19 in England in 2020: A Self-Controlled Case Series Study

Figures & data

Figure 1 Study design with exposure and baseline periods.

Notes: Days 14–0 shown in orange were excluded from analysis and the time intervals shown in green are the strata of the exposed period used in analysis.

Table 1 Baseline Characteristics of Study Population

	All	QRISK3		Hypertension
		Raised Risk	Low Risk	Raised Risk	Low Risk
	N=1762	N=1350	N=412	N=1047	N=715
Sex
Women	702 (39.8%)	504 (37.3%)	198 (48.1%)	399 (38.1%)	303 (42.4%)
Men	1060 (60.2%)	846 (62.7%)	214 (51.9%)	648 (61.9%)	412 (57.6%)
Age group (years)
40–54	327 (18.6%)	84 (6.2%)	243 (59.0%)	154 (14.7%)	173 (24.2%)
55–64	436 (24.7%)	293 (21.7%)	143 (34.7%)	253 (24.2%)	183 (25.6%)
65–74	454 (25.8%)	428 (31.7%)	26 (6.3%)	276 (26.4%)	178 (24.9%)
75–84	545 (30.9%)	545 (40.4%)	0 (0.0%)	364 (34.8%)	181 (25.3%)
COVID-19 associated hospital stay	691 (39.2%)	543 (40.2%)	148 (35.9%)	410 (39.2%)	281 (39.3%)
Median (IQR)	10 (4–21)	9 (4–20)	10 (4–26)	9 (4–20)	10 (4–25)
Died ≤30 days after event	369 (20.9%)	301 (22.3%)	68 (16.5%)	208 (19.9%)	161 (22.5%)
Died in study period	458 (26.0%)	383 (28.4%)	75 (18.2%)	258 (24.6%)	200 (28.0%)
Wave
One	621 (35.2%)	478 (35.4%)	143 (34.7%)	363 (34.7%)	258 (36.1%)
Two	1141 (64.8%)	872 (64.6%)	269 (65.3%)	684 (65.3%)	457 (63.9%)

Figure 2 Study population flow chart.

Table 2 Season-Adjusted Incidence Ratios for Acute Cardiovascular Events Occurring in Exposed Periods After SARS-CoV-2 Infection by Cardiovascular Risk and COVID-19 Wave

Risk Period	All		QRISK3				Hypertension
			Raised Risk		Low Risk		Raised Risk		Low Risk
	N Events	IR (95% CI)	N Events	IR (95% CI)	N Events	IR (95% CI)	N Events	IR (95% CI)	N Events	IR (95% CI)
All
1–7 days	219	7.14 (6.06–8.41)	171	6.97 (5.79–8.39)	48	7.78 (5.48–11.05)	122	6.55 (5.28–8.14)	97	8.04 (6.26–10.33)
8–14 days	88	3.72 (2.96–4.68)	60	3.22 (2.44–4.24)	28	5.62 (3.68–8.58)	46	3.22 (2.35–4.40)	42	4.50 (3.21–6.31)
15–28 days	64	1.74 (1.33–2.26)	46	1.60 (1.18–2.18)	18	2.22 (1.34–3.68)	42	1.86 (1.34–2.59)	22	1.53 (0.98–2.39)
29–91 days	108	1.14 (0.92–1.41)	76	1.05 (0.81–1.34)	32	1.46 (0.97–2.20)	69	1.17 (0.90–1.53)	39	1.08 (0.76–1.54)
Baseline	714	Ref	548	Ref	166	Ref	433	Ref	281	Ref
Wave 1
1–7 days	81	6.01 (4.52–7.99)	66	6.13 (4.46–8.43)	15	5.48 (2.91–10.32)	46	5.39 (3.73–7.78)	35	7.15 (4.56–11.23)
8–14 days	20	1.79 (1.11–2.87)	15	1.70 (0.98–2.93)	5	2.09 (0.81–5.44)	9	1.23 (0.62–2.45)	11	2.83 (1.45–5.49)
15–28 days	26	1.36 (0.89–2.07)	20	1.34 (0.83–2.18)	6	1.40 (0.58–3.39)	16	1.28 (0.75–2.19)	10	1.50 (0.75–2.99)
29–91 days	52	0.72 (0.52–1.00)	36	0.65 (0.44–0.95)	16	0.99 (0.53–1.82)	33	0.69 (0.46–1.04)	19	0.78 (0.46–1.34)
Baseline	165	Ref	126	Ref	39	Ref	102	Ref	63	Ref
Wave 2
1–7 days	138	4.19 (3.35–5.23)	105	3.73 (2.90–4.79)	33	6.62 (4.05–10.83)	76	3.61 (2.69–4.84)	62	5.16 (3.66–7.26)
8–14 days	68	2.69 (2.03–3.57)	45	2.10 (1.50–2.95)	23	5.85 (3.39–10.08)	37	2.35 (1.61–3.42)	31	3.26 (2.13–5.00)
15–28 days	38	0.99 (0.69–1.41)	26	0.80 (0.52–1.22)	12	1.98 (1.00–3.92)	26	1.06 (0.68–1.64)	12	0.85 (0.46–1.59)
29–91 days	56	0.76 (0.55–1.05)	40	0.65 (0.45–0.95)	16	1.36 (0.71–2.63)	36	0.75 (0.50–1.12)	20	0.78 (0.46–1.32)
Baseline	549	Ref	422	Ref	127	Ref	331	Ref	218	Ref

Figure 3 Incidence ratios for first acute cardiovascular events in risk periods following SARS-CoV-2 by cardiovascular event type.