Day-to-day blood pressure variability predicts poor outcomes following percutaneous coronary intervention: A retrospective study

Table 1 Descriptive statistics of variables in data set by adverse event for 471 patients with percutaneous coronary intervention

	No MACE (n = 324)			Had MACE (n = 147)
	n	mean	SD	n	mean	SD
Systolic SD	324	13.72	6.02	147	15.38	5.26
Diastolic SD	324	8.54	3.11	147	8.93	2.71
Systolic LC	324	37.11	14.79	147	44.31	15.42
Diastolic LC	324	23.60	7.78	147	26.37	9.09
Systolic average	324	131.83	11.47	147	132.20	11.63
Diastolic average	324	74.82	7.75	147	71.33	7.64
Number of BP readings	324	40.19	35.86	147	62.81	52.85
Mean days between readings	324	59.07	37.04	147	42.19	30.70
Age	322	67.87	11.21	147	70.69	11.86
Pre PCI LVEF	252	56.44	11.73	122	53.06	13.63
Pre creatinine	307	1.15	0.98	138	1.50	1.19
		n	%		n	%
Sex	469
Male		110	74.83		228	70.37
Female		37	25.17		94	29.01
Race	469
White		142	96.60		312	96.30
Other		5	3.40		10	3.09
Hispanic		1	0.68		4	1.23
Smokes	467	22	14.97		51	15.74
Has hypertension	469	135	91.84		266	82.10
Has diabetes	469	67	45.58		122	37.65
Had prior CVD	469	39	26.53		68	20.99
Had prior MI	470	106	32.72		63	42.86
Had prior PCI	470	125	38.58		67	45.58
Had prior CABG	470	53	16.36		41	27.89
Prior creatinine	445
0 to 2		296	91.36		118	80.27
> 2 to 5		8	2.47		18	12.24
> 5		3	0.93		2	1.36
Anginal class	469
No symptoms		33	22.45		24	7.41
CCS I		11	7.48		39	12.04
CCS II		27	18.37		87	26.85
CCS III		43	29.25		95	29.32
CCS IV		33	22.45		77	23.77
On anti-anginal medication	469	114	77.55		204	62.96
Beta-blockers		98	66.67		164	50.62
Calcium channel blockers		37	25.17		76	23.46
Long-acting nitrates		33	22.45		41	12.65
Ranolazine		3	2.04		2	0.62
Indication	471
Non-STEMI		82	55.78		167	51.54
STEMI		9	6.12		39	12.04
Other stage		56	38.10		118	36.42
MACE within 1 yr	471
Readmission					131	27.81
MI					47	9.98
Death					21	4.46
CVA					6	1.27

MACE: Major adverse cardiac events; SD: Standard deviation; LC: Largest change; BP: Blood pressure; PCI: Percutaneous coronary intervention; LVEF: Left ventricular ejection fraction; CVD: Cardiovascular disease; MI: Myocardial infarction; PCI: Percutaneous coronary intervention; CABG: Coronary artery bypass graft; CCS: Canadian Cardiovascular Society; STEMI: ST-segment elevation myocardial infarction; CVA: Cerebrovascular accident.

Table 2 Receiver operative characteristic analysis of cutoff values for four measures of blood pressure variability predicting adverse events

	Cutoff	Sensitivity	Specificity	AUC	95% confidence interval
					Low level	Upper level
MACE
Systolic SD	12.0	0.7755	0.4475	0.6300	0.5752	0.6792
Diastolic SD	8.0	0.6395	0.5216	0.5674	0.5102	0.6195
Systolic LC	33.0	0.7891	0.4414	0.6510	0.5957	0.7001
Diastolic LC	26.0	0.5102	0.6235	0.5837	0.5262	0.6359
Readmission
Systolic SD	14.0	0.5573	0.6324	0.6348	0.5792	0.6846
Diastolic SD	8.0	0.6565	0.5206	0.5734	0.5149	0.6267
Systolic LC	33.0	0.8168	0.4412	0.6592	0.6039	0.7083
Diastolic LC	25.0	0.5573	0.6176	0.6018	0.5426	0.6549
MI
Systolic SD	13.5	0.6596	0.5684	0.6234	0.5371	0.6967
Diastolic SD	9.0	0.4894	0.6604	0.5730	0.4800	0.6533
Systolic LC	48.0	0.4468	0.7665	0.6609	0.5649	0.7393
Diastolic LC	26.0	0.6170	0.6038	0.6255	0.5370	0.7004

AUC: Area under the ROC curve; MACE: Major adverse cardiac events; SD: Standard deviation; LC: Largest change; MI: Myocardial infarction.