Decrease in platelet count in patients with AKI and its association with major adverse kidney events

Figures & data

Figure 1. Flow chart of the study population.

Table 1. Baseline clinical characteristics of AKI patients according to the hemodialysis treatment.

Variable	AKI without IHD	AKI with IHD	Total	P value
Demographic characteristics
Age [years], median (IQR)	55 (39-67)	52 (38-64)	54 (38-66)	0.16
Male sex [N (%)]	140 (57.14)	102 (65.81)	242 (60.5)	0.08
Weight [N], kg	70 (60-82)	70 (62.65-80)	70 (61-82)	0.84
Systolic, mmHg	120 (105-134)	117 (105-136)	120 (105-134.5)	0.83
Diastolic, mmHg	70 (60-80)	70 (60-80)	70 (60-80)	0.58
Temperature ^oC	36.5 (36.3-37)	36.5 (36-37)	36.5 (36.2-37)	0.39
HR [N]	86 (78-100)	90 (80-100)	88 (80-100)	0.02
Diabetes [N (%)]	89 (36.3)	47 (30.32)	136 (34)	0.21
Hypertension [N (%)]	98 (40)	45 (29.03)	143 (35.75)	0.02
Smoker [N (%)]	30 (12.24)	26 (16.77)	56 (14)	0.20
Chronic heart failure [N (%)]	33 (13.47)	11 (7.10)	44 (11)	0.04
Chronic kidney disease [N (%)]	69 (28.16)	39 (25.16)	108 (27)	0.51
Cirrhosis [N (%)]	9 (3.67)	3 (1.94)	12 (3)	0.32
GFR, ml/min, 1.73 m^2	18.73 (12.01-27.9)	10.03 (6.52-13.29)	14.17 (8.66-22.49)	<0.01
Antibiotics [N (%)]	181 (74.18)	120 (77.42)	301 (75.44)	0.46
Antihypertensive [N (%)]	86 (35.25)	40 (25.81)	126 (31.58)	0.04
Diuretics [N (%)]	102 (41.80)	73 (47.10)	175 (43.86)	0.29
Vasopressor use [N (%)]	61 (25)	54 (34.84)	115 (28.82)	0.03
Statins [N (%)]	43 (17.62)	21 (13.55)	64 (16.04)	0.28
Sepsis [N (%)]	117 (47.76)	62 (40)	179 (44.75)	0.12
Hypovolemia [N (%)]	33 (13.47)	22 (14.19)	55 (13.75)	0.83
Cardiorenal syndrome [N (%)]	45 (18.37)	16 (10.32)	61 (15.25)	0.02
Nephrotoxic drugs [N (%)]	5 (2.04)	1 (0.65)	6 (1.5)	0.26
Shock [N (%)]	28 (11.43)	27 (17.53)	55 (13.78)	0.08
Obstructive nephropathy [N (%)]	26 (10.66)	35 (22.58)	61 (15.29)	<0.01
Hemoglobin, gr/L, mean	9.91 (8.29-12.42)	9.04 (7.85-10.46)	9.5 (8.01-11.63)	<0.01
Platelets 10^3cel/µL , mean	195.8 (125.2-289)	189 (107-272.6)	194 (117.2-283.3)	0.57
Leucocytes 10^3cel/µL, mean	12.26 (8.07-17.56)	13.06 (8.83-18.09)	12.49 (8.45-18.02)	0.32
Glucose, mg/dL, mean	106 (80-142)	115 (80-152)	109.5 (82-146.5)	0.24
Urea, mg/dL, mean	137.7 (90.5-189)	178.8 (138-235.3)	154 (106-208)	<0.01
Creatinine, mg/dL, mean	3.17 (2.33-4.39)	5.71 (4.12-7.93)	3.92 (2.63-6.02)	<0.01
Sodium, mmol/L, mean	136 (131-141)	136 (131-140)	136 (131-141)	0.81
Potassium mmol/L, mean	4.5 (3.9-5.2)	4.7 (4.1-5.4)	4.6 (4-5.3)	0.05
Calcium, mg/dL, mean	7.8 (7.2-8.5)	7.7 (7.2-8.3)	7.75 (7.2-8.4)	0.40
Phosphorus, mg/dL, mean	5 (3.9-6.2)	6.3 (4.6-7.8)	5.3 (4.1-6.9)	<0.01
Kidney replacement therapy
Hemodialysis [N (%)]	--	155 (100)	155 (38.75)	<0.01
Medical treatment [N (%)]	242 (98.78)	--	242 (60.50)	<0.01
CRRT [N (%)]	3 (1.22)	0 (0.00)	3 (0.75)	<0.01
Hyperkalemia [N (%)]	2 (0.82)	46 (29.68)	48 (12)	<0.01
Metabolic acidosis [N (%)]	--	39 (25.16)	39 (9.75)	<0.01
Hypernatremia [N (%)]	1 (0.41)	6 (3.87)	7 (1.75)	0.01
Hyponatremia [N (%)]	1 (0.41)	14 (9.03)	15 (3.75)	<0.01
Fluid Overload [N (%)]	2 (0.82)	46 (29.68)	48 (12)	<0.01
Uremic syndrome [N (%)]	2 (0.82)	57 (36.77)	59 (14.75)	<0.01
Outcomes
< 21% platelet reduction [N (%)]	221 (90.2)	45 (29.03)	266 (66.5)	<0.01
> 21% platelet reduction [N (%)]	24 (9.8)	110 (70.97)	134 (33.5)	<0.01
KDIGO-1 [N (%)]	15 (6.12)	1 (0.65)	16 (4)	<0.01
KDIGO-2 [N (%)]	43 (17.55)	4 (2.58)	47 (11.75)
KDIGO-3 [N (%)]	138 (56.33)	123 (79.35)	261 (65.25)
Acute on Chronic kidney injury [N (%)]	49 (20)	27 (17.42)	76 (19%)
MAKE at 10 days [N (%)]	174 (71.02)	149 (96.13)	323 (80.75)	<0.01
MAKE at 30-90 days [N (%)]	166 (67.76)	124 (80)	290 (72.5)	<0.01
KRT [N (%)]	3 (1.22)	155 (100)	158 (39.50)	<0.01
Mortality [N (%)]	48 (19.59)	39 (25.16)	87 (21.75)	0.18
WRF [N (%)]	238 (97.14)	144 (92.9)	382 (95.5)	0.04

Data is presented in median (IQR) or proportion (%).

Abbreviations: HR: Heart rate, CRRT: Continuous Renal Replacement Therapy, MAKE: Major adverse kidney event, KRT: Kidney Replacement Therapy, WRF; Worsening of renal function.

Figure 2. Box graph of the platelet count every day and per IHD exposure.

Figure 3. Relationships between platelet reduction and patient outcomes.

Table 2. AKI patients platelet count on every day comparing those without IHD and IHD group.

Day	Total	Platelet counts with IHD	Platelet counts without IHD	p value
1	194 (117-283)	189 (107-272)	195.8 (125-289)	0.57
2	177.55 (112-258)	161.75 (94-250)	182.5 (119-284)	0.14
3	173.3 (112-258)	154 (96-242)	185.75 (122-275)	0.01
4	167.5 (107-251)	161.75 (102-233)	173.1 (107-270)	0.22
5	182 (107-268)	174.8 (113-257)	183.2 (94-293)	0.36
6	184.4 (101-264)	178 (100-237)	193.45 (107-283)	0.31
7	212 (127-302)	201 (135-284)	224 (127-310)	0.67
8	202.7 (125-286)	191.5 (142-268)	214 (119-302)	0.59
9	210.7 (127-291)	206 (145-274)	212.5 (110-304)	0.91
10	216.8 (119-298)	208 (124-286)	216.8 (87-304)	0.78

Abbreviations: IHD: Intermittent Hemodialysis.

Table 3. Odds ratio of platelet reduction for the primary and secondary objectives.

Outcomes	Platelet reduction < 21%	Platelets changes > 21%	P
Primary outcome	OR (95% CI)	OR (95% CI)
MAKE at 10 days	0.271 (0.137–0.533)	3.69 (1.875–7.259)	<0.001
Model 1	0.247 (0.124–0.491)	4.046 (2.034–8.048)	<0.001
Age	1.021 (1.006–1.036)		0.005
Male sex	1.29 (0.768–2.169)		0.335
Model 2	0.234 (0.117–0.468)	4.267 (2.135–8.53)	<0.001
Age	1.022 (1.007–1.039)		0.004
Male sex	1.18 (0.692–2.012)		0.543
Diagnosis	0.925 (0.825–1.036)		0.181
Hypertension	0.752 (0.423–1.338)		0.333
Heart Failure	1.21 (0.495–2.96)		0.675
Model 3	0.96 (0.403–2.286)	1.04 (0.437–2.476)	0.928
Age	1.021 (1.005–1.037)		0.009
Male sex	1.153 (0.663–2.005)		0.613
Diagnosis	0.905 (0.802–1.02)		0.104
Hypertension	0.886 (0.491–1.601)		0.691
Heart Failure	1.37 (0.553–3.394)		0.496
IHD	11.35 (4.016–32.118)		<0.001
Secondary outcomes	OR (95% CI)	OR (95% CI)
MAKE at 30-90 days	0.90 (0.563–1.438)	1.11 (0.694–1.775)	0.661
Model 1	0.891 (0.551–1.439)	1.222 (0.694–1.812)	0.638
Age	1.014 (1.002–1.028)		0.022
Male sex	1.531 (0.976–2.403)		0.064
Model 2	0.861 (0.533–1.411)	1.151 (0.708–1.872)	0.568
Age	1.019 (1.005–1.033)		0.006
Male sex	1.424 (0.897–2.259)		0.133
Diagnosis	0.975 (0.881–1.078)		0.626
Hypertension	0.571 (0.348–0.935)		0.026
Heart Failure	1.094 (0.514–2.325)		0.815
Model 3	1.669 (0.856–3.253)	0.599 (0.307–1.167)	0.132
Age	1.018 (1.004–1.032)		0.008
Male sex	1.425 (0.894–2.272)		0.136
Diagnosis	0.965 (0.872–1.069)		0.507
Hypertension	0.612 (0.372–1.009)		0.054
Heart Failure	1.165 (0.544–2.495)		0.693
IHD	2.656 (1.353–5.205)		0.004
Death	2.354 (1.195–4.636)	0.687 (0.395–1.194)	0.183
Age	1.015 (1.001–1.03)		0.047
Male sex	1.382 (0.809–2.358)		0.235
Diagnosis	0.836 (0.741–0.943)		0.004
Hypertension	0.475 (0.264–0.856)		0.013
Heart Failure	0.558 (0.219–1.419)		0.221

Abbreviations: HR: Heart rate, RR: Respiratory rate, CRRT: Continuous Renal Replacement Therapy, NH: non-hyperchloremic, MAKE: Major adverse kidney event, KRT: Kidney Replacement Therapy, WRF; Worsening of renal function.

Table 4. Platelets changes in groups of 30 (10³cel/µL) and or for mortality risk.

Death	Direction	OR	LCI	UCI	p value
Model 1
> 90	Increase	1.178	0.421	3.296	0.754
60 to 89	Increase	1.333	0.404	4.395	0.636
30 to 59	Increase	1.363	0.475	3.913	0.564
0 to 29	Baseline	Baseline	Baseline	Baseline	Baseline
−29 to −1	Decrease	1.919	0.721	5.107	0.191
−30 to −59	Decrease	1.764	0.607	5.126	0.297
−60 to −89	Decrease	2.117	0.620	7.225	0.231
< −90	Decrease	2.926	1.118	7.661	0.029
Model 2
> 90	Increase	1.139	0.406	3.198	0.804
60 to 89	Increase	1.326	0.401	4.385	0.643
30 to 59	Increase	1.323	0.459	3.810	0.604
0 to 29	Baseline	Baseline	Baseline	Baseline	Baseline
−29 to −1	Decrease	1.925	0.722	5.136	0.190
−30 to −59	Decrease	1.680	0.575	4.905	0.342
−60 to −89	Decrease	2.089	0.610	7.156	0.241
<–90	Decrease	2.969	1.130	7.795	0.027
Intermittent Hemodialysis
Model 3
> 90	Increase	1-956	0.347	11.007	0.446
60 to 89	Increase	1.5	0.180	12.459	0.707
30 to 59	Increase	2.083	0.352	12.319	0.418
0 to 29	Baseline	Baseline	Baseline	Baseline	Baseline
−29 to −1	Decrease	4.821	0.883	26.299	0.069
−30 to −59	Decrease	2.343	0.393	13.963	0.350
−60 to −89	Decrease	2.142	0.248	18.498	0.488
<–90	Decrease	5	0.890	28.704	0.068

Abbreviations: OR: Odds ratio, L: Lower Confidence Interval, UIC: Upper confidence interval. Model 1. Logistic regression using death as dependent variable. Model 2. IHD included as an independent variable. Model 3. Logistic regression using death as dependent variable restricted to those who received IHD.

Availability of data

The files and data are in the physical and electronic archive of the Civil Hospital of Guadalajara Fray Antonio Alcalde and can be requested with prior authorization. All the data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.